TOM SWIFT

"THIS is a new kind of scientific expedition," Bud Barclay remarked with a grin, "bringing pygmies out of the Yucatan jungle!"

"A bit different from our space cruises," Tom Swift agreed with a chuckle. "Bud, these small men are not pygmies; just the shortest of their particular tribe of Mayan Indians. Doctors hope to learn a lot by studying them. For one thing, their pulse rate is twenty points lower than ours."

"And speaking as one of those doctors," added Doc Simpson, "we overpriced medical types are also interested in finding out how they manage to live to be over a hundred, on the average. After all, if the secret gets around, people might not need us any more—I might have to go back to school!"

The famous blond-haired inventor was piloting his equally famous Flying Lab high above the rugged Mexican highlands, accompanied by a small crew of friends from Swift Enterprises in Shopton, New York. Bud, his best pal and copilot, sat beside him. The two youths gazed out the big, downsloping viewpane with eagerness as the eastern mountains that hedged the great central plateau of Mexico gave way to the coastal plain. The skyship had left Mexico City only minutes before, streaking almost due east at supersonic speed.

A fourth man stood behind Tom and Bud next to young Doc Simpson, who was the chief physician at Enterprises as well as a researcher in the field of medicine. Chow Winkler, big in all directions and well-seasoned by the Texas sun, suddenly said, "Bet my last grain o’ cayenne pepper those pygmies won’t come!" A born skeptic, he nudged his ten-gallon hat forward toward the bridge of his nose. The chunky, bald-headed man served as chef for the Swifts’ various expeditions.

Chow squinted out the plane window and shook his head worriedly. "We’ll prob’ly end up with arrows in our backs!" he prophesied.

"You’re prob’ly right," Doc nodded; "especially if you keep calling them pygmies!"

"The rest of us needn’t worry about filling their dinner pots." Bud winked at Tom. "One look at a nice plump specimen like you, Chow, and they’ll toss us back on the shelf!"

"Y-y-you mean th-these Injuns we’re lookin’ for are cannibals?" The grizzled cook turned pale deep in the creases of his prairie tan. "Brand my sagebrush stew, I should’ve stayed on home grounds back at Enterprises." Chow made his headquarters at the Swifts’ huge, ultramodern experimental station. It was here that Tom and his father developed their revolutionary inventions.

"Relax, pardner." Tom soothed the Texan with a smile. "Flyboy here is pulling your leg again. The Mayas are really a very fine and peaceful people."

"They ain’t savages?" Chow gulped.

"Far from it. They’re full-blooded descendants of the ancient peoples who ruled here before Columbus and built great temples."

"And practiced human sacrifice," Bud added with an ominous chuckle.

"Not any more, of course," Tom said.

"So they’s contented, happy people nowadays, hmm?" asked Chow with a baleful look at Bud.

"Well," Tom replied, "I guess it depends whom you ask. But we can rule out ritual sacrifice."

Bud continued his affectionate teasing. "The Mayas may be peaceful now, but there are still plenty of jaguars around in the Yucatan jungle. Those big spotted cats can really be mean when they’re cornered."

Chow grinned feebly. "Wa-aal, I’ll stay in my corner if those cats’ll stay in theirs! Say, how long you figure on bein’ in that jungle, Tom?"

"Not longer than a few days, Chow. Doc expects to identify his subject-group quickly. As for me, I just plan to make some field tests of the new camera, then head back to Enterprises. But I couldn’t pass up the opportunity to try out the retroscope on some real ruins that have been weathered by centuries of exposure." Tom had been developing a television-type electronic camera which he hoped to use in restoring, photographically, ancient writing and carving for study by archaeologists.

After winging across the blue waters of the Bahia de Campeche, the three-decker super-jet Sky Queen flew on across the lush green Yucatan Peninsula. Tom now consulted a video-display map to find the tiny Mayan village where they were to pick up the five natives. In keeping with Doc Simpson’s grant from Grandyke University, he was to locate his subjects among the ever-shrinking population of Maya descendents who had largely retained their traditional ways and culture. An ethnographer from the University of Mexico, Professor Castillez, had directed him to the tribal village he had been studying, named Huratlcuyon. He was to meet the Shopton team there.

"Where can we land, anyway?" Bud asked, worried. The terrain below was a dense green mass of tropical rain forest, with the shore of the Caribbean Sea visible off to the southeast. There appeared to be no spot to set down.

"Strange," muttered Tom. "We’re approaching the coordinates where the work crew from Polyuc was supposed to clear a landing spot for us." Polyuc was the only sizable town near their destination; even so, it was a good fifty miles distant, with only winding unpaved roads threading together the various small settlements that dotted the jungle.

Simpson frowned with concern. "Our contacts in Mexico City confirmed that the field had been cleared and finished as of last Wednesday."

Tom looked up and combined his shrug with a grin of reassurance. "Don’t worry, Doc. Even if we can’t land the Queen right off, we’ll work something out."

"Looks as if you’ll have to use your new plane," Bud told Tom.

"Say, boss, that’s right!" enthused Chow. "A few of us can use that there blimp t’get down on the ground, jest like ole Columbus used his little dinghy-boats t’go ashore from his big ships."

He was referring to another of Tom’s amazing new inventions, which he had brought along in the Sky Queen’s hangar-hold. This tiny plane was part jet and part dirigible. After the dirigible’s bag was filled with helium, so the plane could float without power, the bag could then be slowly deflated to bring the ship gently to earth. As Tom hoped to perfect the inflatable balloon-bag apparatus to a point where it could become standard equipment for small aircraft, making disastrous, fatal air crashes a thing of the past, Bud Barclay had nicknamed the craft a "parachute plane," instantly shortened to paraplane by Tom and his crew. It was his first test model that was now in the hold, previously stowed in the Sky Queen in preparation for testing upon the return to Shopton.

"You’re right, Bud, Chow." Tom turned back and spoke over the cabin microphone to Slim Davis. "Report to the flight compartment!" He then changed frequencies and called Professor Castillez on the ground.

"We can see you, Tom," radioed the ethnologist. "You’re about two miles west of north."

"I’m amazed we can’t see you, Professor."

"Ah, blame the jungle for that!" was the wry response. "And of course Huratlcuyon is very small, and blends in very well with the landscape. But we will see each other shortly, at any rate."

Despite the difficulty it took only a minute more to sight the village far below—a cluster of about fifteen oblong huts, green and brown in color. Cutting the main engines, Tom fed power to the jet lifters to hold the ship steady in its present position, hovering at 3100 feet. Slim, a veteran Enterprises pilot and a good friend of Tom and Bud, entered the compartment a moment later.

"What’s up, skipper? We almost there?"

"The village is right below, but we’ll have to use the paraplane for a landing," Tom explained. "Bud and I will get it ready. Take over."

"An’ I’m comin’ along," Chow declared.

As Slim eased into the pilot’s seat, Tom discussed with him the plan for here on out. He was to pilot the big craft a dozen miles back along their route, to a broad low plateau they had spotted, barren of underbrush and large enough to accommodate the Flying Lab. "A road passed nearby, and we’ve caught glimpses of it now and then as we’ve approached Huratlcuyon. Once you’re down we can use Professor Castillez’s truck to ferry the equipment over—may take two trips, though."

Tom, Bud, Doc, and Chow hurried out through the passageway and down the metal stairs to the cargo hold, a true flying hangar that filled half the Sky Queen’s bottom deck. The sleek little paraplane, its wings folded neatly back parallel to the fuselage, awaited them in its launch-cradle. Other auxiliary craft customarily brought along in the hangar had been left at Swift Enterprises for regular inspection and repair, giving the paraplane plenty of room.

"Mighty cute. But now that I see ’er—jest how we goin’ to float down in this contraption?" Chow eyed the strange-looking craft uneasily. "I thought it was s’posed to have some kind o’ balloon ’r gas bag ’r somethin’. But I sure-t’-hey cain’t see how you’d go about fitting somethin’ like that inside sech a dinky li’l ole thing." The fuselage of the domed, wedge-nosed jetcraft was scarcely bigger than a compact car!

"Don’t let her modest size fool you," Tom replied with a smile. He reached over and patted a long rounded bulge on top of the fuselage that ran its length like a backbone. "The dirigible bag is deflated now and stowed inside this pod. We’ll blow it up with helium as soon as we’re airborne. It inflates almost instantly, like the safety airbags in cars."

"Okay, if’n you say so. But don’t wait too long, Tom!"

As several crewmen stood by in the hold compartment, watching with interest, Tom and Bud checked over the paraplane and readied it for launch, and Doc Simpson and Chow climbed into the cabin of the paraplane, Doc clutching a canvas bag of medical equipment. The interior of the craft was set up like the passenger compartment of a car, one pair of seats side-by-side in front, a second row just behind. Tom took his place at the controls and adjusted his headset as Bud climbed in next to him.

"All ready, skipper?" Slim’s voice came over the earphones.

"Thumbs up!" Tom exclaimed excitedly. "Lower away!" Then Slim pressed a button on the main control board. As an alarm sounded, all the crewmen who had come down to watch hustled out of the compartment. The metal deck began to descend like an elevator platform, lowered by piston-muscled struts. Twenty-two feet below the Flying Lab’s fuselage, a gentle bump announced that the deck had reached position.

A light blinked on, signaling all clear. Tom warmed up the engine, his heart pounding. Although he had test-flown the paraplane back home in Shopton, this would be its first real tryout under different atmospheric flight conditions.

Chow gripped the sides of his bucket seat, pop-eyed with excitement. Bud Barclay flashed the young inventor a tense grin. "Here goes, pal!"

"You said it!" Tight-lipped, Tom flicked a switch to release the spring-chocks and open the throttle.

With a mighty swo-o-oosh of jet power, the paraplane shot out from the Queen’s suspended hangar platform! An instant later, before they had even cleared the stratoship’s tail, the wings of the craft swung outward from the fuselage, snapping into position so quickly they looked like the blades of a fan.

As the wings bit into the airstream, Tom expected them to provide a smooth lifting effect. Instead, the ship gave a lurch that almost jarred the three occupants from their seats. Chow’s foghorn bellow whooped a nervous "R-r-ride ’em, cowboy!" White-faced, he tried to force a grin as the small craft rocked and rolled alarmingly.

Tom fought the controls and managed to steady the ship. Then he steered it in a tight swooping circle to an altitude several hundred feet below the hovering Sky Queen.

"Now to try out the gas bag." Tom’s fingers flew over the control panel. With a muffled sound the pod split open along its length and the big balloon-bag shot out and upward, stretching to its full extension in the space of two seconds as Tom’s boggling passengers craned their necks to get the view above them.

"Now I’d call that fast!" marveled Doc Simpson. "I suppose it’s the helium you pump in that makes the bag go rigid, eh?"

"Nope!" Happy with the smooth operation of his invention, Tom shook his head nonchalantly. "The material of the liftbag is transifoil, interwoven in long, airtight strips. That’s why it has a metallic sheen to it."

"Transifoil," Bud repeated. "That’s the stuff you invented for your space solartron’s atom-snatchers."

"Oh yeah," said Chow. "The stuff that unfolds itself, then folds itself back up, no muss no fuss!"

"That’s it," said Tom. "Tough, durable, lightweight, and ultra thin—just a few angstroms thick, much thinner than a human hair."

"Even thinner than your hair, Chow!" gibed Bud.

"That there’s mighty thin, all right!"

"Anyway," Tom continued as the paraplane drifted to a gentle stop and hung suspended, "I fed the transifoil a trickle of current, and it unfolded and became rigid on its own." He added that it was the expansion of the liftbag as it was made rigid that sucked the helium up into it at supersonic speed, rather than the reverse. "The transifoil’s strength helps resist the pressure of the surrounding air, so we can get by with helium at very low pressure and weight. That allows us to keep the bag fairly small, too."

The liftbag had taken over completely the function of supporting the plane, and Tom cut his jet power. They were floating almost motionless above the jungle.

"Shucks, I knowed all the time it was goin’ to work jest fine," Chow told his young boss.

"Wait till he starts letting the gas out of the bag," Bud teased. "We still have to get down, you know." Chow swallowed hard but said nothing.

"I know you use pumps to release and recompress the helium," Simpson commented. "Where do you store it?"

"We store it in liquid form," explained the young inventor. The helium tanks, supercold and well-insulated, were mounted in a small compartment at the rear of the cabin. As it was now time to descend, Tom switched on an electric pump and compressor apparatus to suck the helium back into the main tank. A humming noise filled the cabin. "We take it much slower during the recompression phase," Tom said, "so we won’t drop too quickly."

"Boss, fer that I thank you kindly!" said Chow.

"You know," Tom continued, "the basic idea for the paraplane came from Great-Grandfather Tom, who worked a lot with dirigible inventions. In the early 50’s, after he’d retired, he tried to get Swift Construction interested in it, but no go."

"What’d he call it?" Bud inquired.

Tom grinned. "The Flexible Flyer!"

As the bag deflated, the paraplane descended, very gently, toward the lush treetops.

"Looks like we’re drifting away from the village," murmured Doc.

"The wind." Tom touched the controls. "This special jet engine can throttle-up almost instantly from zero, and it can idle, like a car in a driveway. That should be enough to nudge us where we want to go."

"I’ve got to hand it to you, genius boy." Bud slapped his chum on the back. "This new invention of yours may save a lot of lives some day."

"I hope so," Tom replied modestly. "In the meantime, let’s also hope we don’t get hung up in one of those trees down there."

Although Tom made no mention of it to Bud or Chow, a new worry came to mind. Despite all preparations, how would the natives greet these strangers from the sky who wanted to take away some of their citizens for scientific study? The medical college of Grandyke University, located near Shopton, had made careful arrangements through the University of Mexico and the aduana—the combination immigration and customs department of the Mexican government—for five healthy young Mayan men to be flown back to the States. But what if the strange aerial arrival panicked them into hostile action!

Still keeping his thoughts to himself, Tom steered the ship gently downward by means of the rudder and elevators, then finally retracted the wings. He aimed for a tiny open space in the forest about one hundred yards beyond the perimeter of the village. Presently a crowd of bronze-skinned native Indians came into view through the densely clustering green foliage.

"A reception committee!" Bud exclaimed.

"Reckon they look friendly enough," Chow added, his Adam’s apple bobbing up and down nervously.

Tom smiled in cautious relief as he saw the natives waving at them. He waved back and urged his three companions to do likewise. The crowd gave way good-naturedly as the paraplane puttered closer to the open space.

Suddenly, as the craft was about to clear the last of the tall trees, the paraplane gave a shudder. Her crew lurched sideways against their safety restraints.

"Good grief!" Tom gasped. "We’re losing pressure in the liftbag—fast! Hold on!"

For a few frantic moments the paraplane dropped like a stone, crashing through the boughs of the trees. Then its flight ended with a violent thud as it smacked down hard against the jungle floor!

TOM SWIFT swiveled frantically in his seat, springing his safety straps with a single quick sweep of his hand. "Everyone all right? Anybody hurt?"

"I’m okay, Tom," Bud replied.

"Me too," said Doc Simpson. "I think our public image may have suffered, though."

"As fer me, I got a few aches an’ pains," Chow grumbled. "Then again, I’ve had ’em fer years, so I reckon it don’t matter. Think my new tooth may’ve got a little rattled, though." He felt with his tongue. "Naw. Guess it’s all right."

When the four airmen emerged, unsteadily, they were greeted by shouts of welcome. The Mayas surged forward in friendly yet dignified fashion to inspect their visitors. Some offered large bouquets of gorgeous-colored flowers.

Tom whispered to Doc, "I don’t think they realize our hard landing wasn’t exactly as planned." The medic chuckled in response.

"Sure are happy little critters!" Chow observed, grinning the whole distance from ear to ear in relief.

The natives were handsome and brown-skinned, with fine figures. But none were over five feet tall, and many of them were considerably shorter. The men were clad only in shorts of some rough fabric, while the women wore simple, straight white dresses, with low square necklines embroidered in gay colors and a matching trim on the skirts.

A swarm of naked little children hugged the legs of their parents and peeped out bashfully at the strangers from the sky. Many of the natives chattered to one another in a strange tongue.

"What kind o’ lingo is that?" Chow asked.

"Old Mayan," came a voice in cultured English, touched with accent. "But many of these people also speak Spanish." A tall, distinguished looking man in glasses had entered the clearing from the underbrush. His skin, burnt dark by the sun, contrasted vividly with his snowy-white hair.

"Professor Castillez?" asked Tom, extending his hand.

The man nodded, offering a firm handshake. "I am glad to meet you, Tom. I thought you would be landing within the village, so I waited behind."

"I didn’t want to risk bumping any of the houses," Tom said. "The paraplane is a new invention, and, as a matter of fact, we had a bit of trouble during the descent." He glanced back and noted that the liftbag, all but devoid of helium, was now leaning far over on its side and resting against the trees, its shape still held rigid by its transifoil strips.

"Tell me, Professor—do you know what became of the team of workers that were to construct a landing field for our big jet?" Doc inquired as he shook hands.

"I had assumed it had been completed," was the reply. "Then again, the workers had not planned to stay here in Huratlcuyon. I merely assumed they had done their job somewhere out of sight in the jungle. One can hardly see more than twenty feet ahead, you know." Castillez turned back to Tom. "This delegation of our most eminent citizens has come to welcome you, my young friend."

Before Tom could essay a speech of reply to this friendly welcome, a stalwart old Maya raised his hand. Castillez whispered that he was chief of the village. At the chief’s signal, the crowd parted and a group of men dancers came forward. All were adorned with tall headdresses of parrot feathers. While several other Indians beat oddly fashioned drums and blew on conch shells, the group began to perform a ceremonial dance.

"Brand my turkey giblets," Chow gasped, "they’re actin’ like birds!"

"I think that’s what they’re supposed to be imitating," Tom replied softly.

The dancers gracefully hopped about, flapped their arms, and made pecking motions at each other.

Finally the performers finished and the three Americans applauded loudly, to which the dancers responded without smiles but with sober dignity. As they withdrew, the chief stepped forward again.

Tom clasped his hand and spoke a few words to him in Spanish, which the chief appeared to understand. The young inventor then handed over several papers from the Mexican authorities, identifying the American visitors and stamped with an official seal. The man responded in halting Spanish.

Embarrassed, Tom confessed that he had not caught what the chief had said.

"Ah! He says he’s the ahau, or king, no less, of these people!" explained the Professor. "And that his Spanish name is José," he added. "But we’re to call him by his Mayan name—Hu-Quetzal."

"Quetzal?" Chow shoved back his ten-gallon hat and scratched his bald dome. "Ain’t that a bird too?"

Tom nodded. "It’s rare now, but the quetzal is a beautiful bird with brilliant long green plumage. It was sacred to the ancient Mayas."

"They seem to be very fond of their feathered friends," Bud chuckled.

When Quetzal finished looking over the documents, he handed them back to Tom very gravely and ceremoniously. Then he beckoned forward five of the young Mayan men. All were very short in stature. "These are the favored ones, the best of our village," the chief said to Tom.

"Oh, you speak English, sir?" Tom responded in surprise as Quetzal introduced them by name to the Americans.

"I do now. Now, we have been introduced as two chiefs, by these papers. But I say, I only speak it a little bit, like a small pebble. Now then, muy bien, my tribe and I desire that you stay at our village for the night," Quetzal went on. "We will have more entertainment for you."

"Thank you for your kindness," replied Tom with a slight bow. "If you will permit us, we would like to stay with you several days." The ahau nodded his approval.

Chow scowled suspiciously and murmured into Tom’s ear, "You figure that’s safe?"

Tom grinned. "Still worried about those stewpots, Chow? I’m sure that we can trust these people."

"We are a safe people. Hospitality is a sacred duty to us," stated the chief.

Chow reddened but said, "Well, sure—jest like in Texas, Mr. Quetzal."

Turning back to Hu-Quetzal, Tom added that they must first notify the other Americans, who by now had landed in the Sky Queen, that they had arrived.

The chief nodded. "You come to the village when you are ready. My people and I will return there and make preparations. I must tell you, Tom-Swift, that few of our children have ever seen a man with gold hair like yours. They may…" He paused and murmured something to Castillez.

"They may stare at you," the Professor translated; "but no discourtesy is intended."

Then Hu-Quetzal turned and led his people away down a narrow, all-but-invisible jungle path.

The four visitors reentered their plane and Tom reported by radio to Slim Davis.

"The Queen’s down and safe," Davis replied. "Same as you boys, sounds like."

Tom snorted. "Well, we’re down. Batten down the hatches for the night," he said. "I’ll call you tomorrow morning when we’re ready to leave in the truck."

"Roger!" Slim acknowledged. "We’ll have the camera equipment packed up and ready."

Chow was still grumbling about staying overnight in this strange place as he climbed out of the paraplane with Tom and Bud. Suddenly the well-weathered Texan broke off with a gasp of fear and grabbed Tom by the arm.

"What’s wrong now?" the young inventor asked.

"L-L-Look!" Chow gulped, pointing with a trembling finger.

Tom heard a bloodcurdling snarl. Then, on the lowest branch of a nearby tree, he saw a ferocious-looking jaguar, its mouth open and its teeth bared.

The next moment the crack of a rifle rang out!

As the sound of the shot died away, the jaguar leapt up the trunk of the tree and disappeared among the upper foliage.

"Quick! Into the paraplane!" Tom ordered. "That big cat might come back!"

"Who fired that shot?" Bud demanded. The muscular, dark-haired young flier was pale and shaken by their narrow escape—and their unexplained rescue.

"Just what I want to know," Tom said, peering out the window. "And was it meant for us, or for the jaguar?"

Bud straightened up with a fresh shock. "Hey! Are you implying that we have human enemies in this jungle? I thought this time we were going to get a vacation!"

Tom shrugged thoughtfully. "That rifleshot was fired at close range, yet it missed the jaguar completely."

Bud exchanged worried glances with Chow and Doc Simpson. Dangerous adventures were nothing new to Tom Swift, as they all knew from perilous experience. Soon after perfecting the Flying Lab, his first major invention, 18-year-old Tom had been forced to match wits with deadly rival factions in South America. Other adventures had followed, not only undersea and at the South Pole, but even in outer space. In his latest exploit with his space solartron, the young inventor had rescued his father from mysterious space agents in his revolutionary spaceship, the Challenger.

Tom decided to test the unknown rifleman’s intentions. Plucking a white handkerchief from his pocket, he opened the cockpit door and fluttered it outside the plane.

The signal was greeted by a shrill laugh. A moment later a white man strode into view, carrying a high-powered rifle in his hands and a knapsack over one shoulder. He wore braided khaki breeches and an embroidered shirt, and a pith helmet. He gave them a friendly nod.

"Brand my iguana stew, who’s this critter?" Chow demanded in low tones. He stared at the newcomer in frank surprise.

"Let’s find out," Tom replied.

"And don’t mention iguana stew!" added Bud.

The four Americans clambered from the plane to meet the stranger face to face. He was of medium height, slightly pudgy, and conveyed an air of careless elegance, his eyebrows slightly raised in what might have been a smirk. Before speaking, he took out a silk handkerchief and dabbed his face delicately.

"You came along just in time." Tom smiled and held out his hand.

"De nada. Buenos dias." The stranger shook Tom’s hand with the tips of his fingers. His grin seemed slightly mocking.

"Are you Mexican?" Bud asked. He was puzzled by the stranger’s manner. Also, his brownish-blond hair and light complexion seemed unusual for a Latino American.

"Mmm, well, I was born in Boston," the man replied in a languid voice. "Actually, I consider myself neither an American nor a Mexican."

"Meaning what?" Bud asked bluntly.

"Meaning no offense. Let’s say I prefer to call myself an internationalist." As Tom and Bud flashed each other quizzical glances, he went on suavely, "I’m down here studying archaeology and philology at the University of Mexico. My name is Wilson Hutchcraft."

Tom introduced himself and his three companions. Chow added suspiciously, "What’re them two things you said you ’as studyin’?"

Hutchcraft smiled patronizingly at Chow’s question. "Archaeology and philology. The first is the study of the material remains of ancient cultures."

"Oh. I knew that one a’ready. You’re one o’ them fellers who dig up old stones an’ mummies an’ sechlike, hey?"

"You might put it that way. Philology, on the other hand, is the study of languages. I speak several, and just now I’m doing field work, learning various Indian dialects."

"Including Mayan?" Tom asked.

"Naturally," Hutchcraft replied. "Mayan, Chichimoc, Old Nahua. That’s why I’m here in this godforsaken jungle. No doubt you know that there are four branches of the Mayan tongue—Main, Aguacateca, Chuje, and Jacalteca. But I’m very much interested in the local tribe because they use certain words and phrases which differ from any of those dialects."

Chow fanned himself with his ten-gallon hat and shook his head. "Sure sounds like gobbledygook to me."

"I’d advise you to refrain from expressing that sentiment to your hosts here," said Hutchcraft. "They believe in revenge-killings and are crafty and determined hunters."

"Anyhow," Tom said with a laugh, "it’s lucky you happened along with a gun just now.’’

"If you’re wise, you’ll carry guns yourselves," Hutchcraft warned. "This jungle country can be dangerous."

Tom made no reply to this suggestion. In the spirit of the famous Swift family of scientist-inventors, he felt that scientists should work for the peaceful advancement of mankind. In line with this belief, weapons were used only as a necessity on Swift expeditions.

Changing the subject, Tom explained the purpose of his flight to Yucatan. He invited Hutchcraft to join him and his friends in their visit to Hu-Quetzal’s village.

"Delighted," the Bostonian replied. "As a matter of fact, I was on my way there just now. The road, if you’ll pardon the exaggeration, is just over that rise, to your left. I was let off by one of my colleagues, who will return for me a week from Thursday. But tell me, what sort of airplane is that?"

"An experimental one," was the brief answer. "And that reminds me, I need to fold and stow the liftbag before we leave—and before doing that, I want to see if I can determine what caused it to spring a leak on us."

Hutchcraft did not comment. He pulled out a bottled softdrink, a Mexican brand, and took a long gulp.

Tom again entered the paraplane’s cockpit and manipulated the controls, reducing the current to the transifoil. The liftbag began to bend and fold-in on itself, in the process forcing out whatever gas was left inside.

"You’re not recompressing it?" asked Bud through the open door.

"No point in that," Tom grimly replied. "By now it’s almost all air. Fortunately there’s a full helium reserve tank in back, which we can use once the rip is fixed—we’ll bring the mending equipment from the Flying Lab tomorrow."

When the bag was partially folded and within a hand’s-reach of the ground, Tom increased the electric current slightly to halt the refolding process. Then he climbed out and began to inspect the bag with his keen eyes, circling it. After a minute he called out, "Well, there’s the puncture!" He pointed.

"What’s that sticking out of it?" asked Doc. "A branch?"

"Let’s see." Tom climbed up on the fuselage and grasped the rodlike object, pulling it out.

"Wa-aal, brand me fer a popeyed armadiller!" exclaimed Chow. "It’s a arrow!"

"A mighty big one," Tom agreed. He scrutinized it, turning it over in his hands. "Funny. It’s made of some kind of hard, light, polished wood. And look at the arrowhead." The arrowhead, fluted along its length, had sides that curved smoothly inward to a point that looked fierce and unforgiving. "I’ve never seen an arrowhead like this—have you, pard?"

"Nope," Chow replied, puzzled. "And I’ve seen my share."

"If you don’t recognize that," said Hutchcraft in smug tones, "you’re hardly prepared to do serious archeology here in Maya-land. It’s a t’cunda."

"Oh—right." Bud had become irritated at Hutchcraft’s insulting manner. "Used for shooting down blimps!"

The archaeologist smiled blandly. "It’s a type of arrow—almost a javelin, actually—made by expert artisans for the Great Ahauxpa, the Priest-Emperor of all the Maya. It was a sign of status, and only the sacred warriors of the ahauxpa were allowed to carry them. For anyone else to even touch one constituted a capital offense. But," he added, "that was more than a thousand years ago, of course."

Tom leapt down and held out the arrow for Hutchcraft to see close-up. "This hardly looks ancient to me."

"No," Hutchcraft admitted; "obviously made rather recently. I suppose the technique has been passed down the generations."

"Well, it’s a mighty high-tech gadget if it can rip a hole through the material of the liftbag," Tom declared. "Even a high-powered rifle like yours would have some difficulty." Suddenly something seemed to catch his interest. He drew the point of the t’cunda closer to his eyes, turning it in the sunlight. "What’s this fastened to the tip? It reflects light like a sliver of crystal."

Doc Simpson asked if the traditional arrows had been finished in such a manner. Hutchcraft shook his head. "No. Never heard of such a thing. What sort of crystal is it?"

Tom was silent for a moment. Then he extended his hand, gesturing for Hutchcraft to hand him his soda bottle.

"A bit of brain stimulant, hmm?" was the man’s comment as he handed it over.

But Tom did not take a sip. Grasping the arrow firmly near its head, he scraped its point down the side of the glass container. All the watchers could see the fine white scratch it left behind.

Tom looked up at them. "To answer your question, Mr. Hutchcraft, the crystal is diamond—the hardest common substance known to man!"

THE ONLOOKERS from Shopton gaped in amazement at Tom’s quiet pronouncement, and a twitch of interest even seemed to ripple across Wilson Hutchcraft’s smug countenance. "Diamonds!" repeated Chow. "You mean that there arrow’s worth a bundle o’ money?"

"It’d be worth a bundle to me to find out where it came from," responded Tom dryly.

"This is quite unprecedented," Hutchcraft said. "Diamonds are not found in Yucatan."

Tom nodded. "I know that, at least. The whole peninsula is a limestone shelf underneath, not mining country."

"Well, skipper, I’d say somebody went to a lot of expense and trouble to bring down your paraplane," observed Doc Simpson soberly.

Bud had a look on his face that Tom recognized immediately—suspicion tinged with anger at the threat to his friends. "Right. Another one of those ‘somebodies’ who picks Tom Swift as a target and then runs off and hides. And say—" Bud suddenly turned to Hutchcraft. "You were traipsing through the jungle around that time, weren’t you, Hutch?"

The archaeologist frowned. "I don’t care for your insinuation, young man. From what has been said, I was a good half-mile down the road when your plane was attacked. And I really don’t care whether you believe me or not."

Tom tried to smooth over the awkward moment. "No one’s accusing anyone. Look, it’s getting late. Let’s take the chief up on his offer and head toward the village. Come along with us, Mr. Hutchcraft. I’m sure Hu-Quetzal will allow you to share the accommodations offered us."

The man smiled his irritating smile. "They do have a reputation for hospitality."

"Yeah," Chow muttered under his breath, "when they ain’t huntin’ you down!"

The paraplane was secured and locked up. Then, with Tom in the lead, the five started down the thread-narrow jungle trail toward Huratlcuyon. Twilight was falling over the steamy green rain forest, and the chattering birds began to hush. But the fading sunlight brought no cooling breeze to relieve the damp, oppressive heat of the Yucatan lowland. All five travelers were soon perspiring heavily as they tramped over the matted jungle path, and Hutchcraft’s big handkerchief was in constant flutter.

"The village is right ahead, guys," Tom announced presently. "I can see it between the trees."

Hu-Quetzal’s domain was little more than a huddle of palm-thatched huts. Cooking fires blazed in front of every dwelling. The women, crouched over open stone fireplaces, were patting tortilla cakes out of corn meal for the evening repast, while men chatted in squatting groups and children played nearby. Seeing Tom and his companions, the children fell silent, looking at them with wide eyes.

Professor Castillez emerged from a small tent to meet the troop. After Wilson Hutchcraft had introduced himself, Tom showed Castillez the arrow, which he had carried along with him in his hand. "Milagro a Dios!" gasped the man. "A diamond! But who would use such a thing to attack peaceful visitors?"

Hutchcraft snorted. "As I understand it, whole areas of southern Mexico are in a state of resistance to the central government. And I’m not speaking of quiet picketing."

Castillez nodded slowly. "Si si, es verdad—the Chiapas problem. Perhaps… but who can tell by one arrow, eh?"

As Ahau Quetzal came forward to greet the visitors, Tom showed him the strange arrow, then said, "This is a new friend of ours, also a North American," and introduced Hutchcraft.

As expected, Quetzal invited the newcomer to stay, then took the visitors to a central fireplace, which Tom assumed served for village ceremonies and celebrations. "I hope you will accept gifts of food from my people and that you will enjoy them," the chief said.

The gifts turned out to include a roasted wild turkey, a heaping supply of papaya fruit, guavas, bananas, and avocado pears, as well as several gourds full of coconut milk.

"Brand my lil ole cookstove, we got enough grub here for a reg’lar feast!" Chow gloated. "Afore we get gone, I’m gonna try fer a few recipes t’take back."

The Americans ate with hungry zest. Even Hutchcraft, who had made several sneering comments under his breath about the primitive cooking conditions, admitted that the meal was very good, if exotic in its mix of flavors.

By the time they finished, darkness had fallen. The sky over the jungle was brilliant with stars. "Sure is purty up there," Chow remarked, staring heavenward. "But it’s even better back home in Texas," he added quickly, doing his patriotic duty to the Lone Star Republic.

Quetzal, who ate in a separated area, announced the arrangements for the night. "You will all sleep in my own house—the house of the ahau," he told them proudly.

Like the other dwellings in the village, the hut was made of saplings covered with mud. It was rectangular in shape, about twenty-five feet long, with walls ten feet high and a steep, palm-thatched roof. Although it had no windows, there was a doorway in the middle of each long side.

Hammocks woven of henequen fiber were slung side by side in a row between the two open doorways. Thick rough-hewn wooden posts, planted deep into the ground, held up each end. This arrangement, the chief explained, was to enable sleepers to catch the trade winds which occasionally wafted through the jungle. He also provided a modern innovation, mosquito-netting covers for each hammock.

"I think I’d prefer sleeping out in the fresh air," Hutchcraft announced, sniffing the atmosphere of the hut disdainfully. Not asking permission, he proceeded to unsling one of the hammocks.

"Reckon I’ll do the same," Chow said. "No offense, Mr. Quetzal, sir—jest think I might need t’stretch out a little."

But Hutchcraft’s next remarks made Chow change his mind. "After all, I have a rifle and you don’t," the Bostonian reminded him. "That jaguar might still be prowling around."

Chow gulped. "Mebbe I’ll wait with th’ stretchin’ until tomorrow morning."

Soon the village was wrapped in silence. The four Americans in the hut quickly fell asleep. But suddenly Tom was awakened by a thunderous crash, nearby enough to jar the mat-covered floor!

"Huh? Wh-what’s going on?" Bud muttered thickly, trying to sit up in his hammock.

"Don’t know yet," Tom replied tersely, fumbling in the darkness for his flashlight. Was it another attack by the mystery bowman? In a moment he extracted the flash from one pocket of his trekking breeches, which he had hung on the wall nearby. As he switched on the beam, Bud came wide awake and gave a roar of laughter.

Chow, still half asleep, was sprawled on the floor of the hut, hopelessly tangled in his mosquito netting. He blinked and snorted in the dazzling yellow glow of the flashlight.

"What in thunderation happened?" the ex-range cook grunted.

"Guess you fell out of your hammock," Tom replied, stifling his own laughter so as not to embarrass his friend. "Come on. I’ll help you up."

Chow was hardly back in his swaying billet when loud snores announced that he was fast asleep again.

Tom chuckled. To Bud he whispered, "The fall didn’t hurt him."

"Bet it hurt the floor, though," was the mischievous response.

The next morning, after a breakfast of melons, Tom was eager to be off to the Sky Queen in Professor Castillez’s truck. But again Ahau Quetzal delayed him.

"First we must have the ceremony of the second day," he told Tom politely but firmly. "You have spent the night with us, eaten our food with us; now we must give you the traditional blessings, for good fortune and protection."

"Primitive nonsense," muttered Hutchcraft.

But Tom accepted the chief’s request gracefully. "We may need a little extra luck," he told his companions with a chuckle.

The entire tribe gathered around the stone fireplace in the center of the village. All bowed their heads as a priest of the native race, passing through from a church in another small village some miles distant, blessed the guests from America and offered prayers in Spanish.

"The imported faith of the new society," commented Castillez softly. "For these people, all that has happened in Mexico since the time of Hernan Cortés is recent! Now you will see a remaining trace of the old religion, which the Europeans were never able to extinguish."

A Maya, taller than the others, stepped forward. He wore arm bands of worked metal, shell necklaces, a skirt made of jaguar skin, and a parrot-feather headdress.

"Now the real show begins," Hutchcraft whispered contemptuously to the other Americans as he stood a ways back. "This fellow is a shaman, a medicine man. He and his sort cling stubbornly to the pagan practices of their ancestors. The Church tolerates it. Not that they have much choice."

Several native bearers brought a large flat stone for the medicine man to stand on, He mounted it and began to utter an incantation in what Castillez explained was the old Mayan tongue, much corrupted with time.

Suddenly Tom’s eyes bulged in surprise. The stone bore a number of odd carved symbols, which the young inventor had at first assumed were purely decorative. But as he looked more closely they began to appear strangely familiar. Good night! he thought excitedly. Space symbols! I’m sure of it!

Groupings of similar symbols, mathematical concepts expressed through geometrical figures, had been found on a missile from outer space which had landed on the grounds of Swift Enterprises under the exacting direction of unknown extraterrestrials. Tom and his father had managed to decode the message and to reply by means of a powerful radio transmitter. Later, signals had been picked up with a special receiving antenna, using an oscilloscope-type imaging screen. Assisted by a slowly-growing "space dictionary" in computer form, they had become increasingly proficient at interpreting the halting, strangely oblique messages from space.

Almost without realizing it, Tom stepped forward to get a better look at the stone. The carvings on it were faint, almost weathered away.

A muscular native grabbed his arm and jerked him back. "Do not interrupt the sacred ceremony!" the man hissed in broken Spanish.

Tom waited tensely for the ceremony to end. He could hardly contain his curiosity as questions surged into his mind.

Was he mistaken about the carved symbols on the stone? Or were they really the same as those used in messages from his space friends? If so, how had they happened to appear in this remote jungle village?

Bud inched close and nudged his pal. "Am I seeing things?" he whispered. "Those carvings—"

"We’ve got to find out!" Tom murmured with fierce intensity. "We may have stumbled on a fantastic discovery!"

"WHAT’S wrong, boss?" Chow Winkler asked, approaching and noting Tom’s puzzled frown.

"Take a look," Tom whispered, pointing to the stone on which the medicine man was standing. "Do those carvings strike you as familiar?"

Chow gasped in amazement. Doc Simpson was also dumbfounded as his eyes followed Chow’s pop-eyed stare. Both recognized the symbols immediately.

"Brand my buckboard!" Chow muttered under his breath. "They look jest like the stuff that comes through on the space TV—them squiggly pictures!"

Tom nodded. "I certainly want to get a closer look."

As soon as the Mayan medicine man finished his incantation, the bearers lifted the stone to take it away. Tom touched Hu-Quetzal’s arm.

"May I see the carvings on that stone? I find them very interesting."

The ahau’s eyes narrowed. He pondered a moment, then said, "Muy bien." He signaled the bearers to bring the stone over to Tom, adding, "But remember, mi amigo, you are gazing on our most sacred possession."

Sacred! This made the find even more important, Tom thought.

He bent low and scrutinized the carvings. Some of the symbols were so weathered and faded that they could hardly be seen. But calling upon his memory, Tom was able to decipher at least part of the inscription. His heart beat with a thrill of discovery!

Looking up at Ahau Quetzal, Tom pointed to one cluster of interlocked symbols. "‘Fifty of us came here without mishap’."

The effect on the chief was amazing! His month dropped open and an expression of awe and fear came into his eyes. Grabbing Tom by the arm, Quetzal drew him aside from the crowd of natives. "You are right!" he gasped. "But how did your eyes know of this, Tom-Swift? Can you read this writing carved by our ancestors many great-suns ago?"

"Some, but not all of it," Tom replied. "You see, I have received messages in such writing myself—from people somewhere in the sky."

"In the sky?" The man looked at Tom blankly. "Do you mean, perhaps, some planet in space?"

Tom grinned at his own assumptions. Using simple terms, Tom summarized the history of the communications received from the friendly space scientists, which both he and his father were certain came from other-worldly beings possibly stationed on the planet Mars.

Chief Quetzal’s eyes grew wider and wider as he listened, even though it was clear that he failed to understand all of what Tom was saying.

"Do you say that some of our ancestors came from the far-place on the other side of the sky? A planet? But it must be so!" Quetzal exclaimed proudly. "This stone has always belonged to my people. Unfortunately," he added sadly, "we have lost the voice of the old ones. The meaning of only one other part of the stone-words has come to us from the ancients."

Pointing to another group of symbols on the stone, Quetzal translated: "‘Now we will hunt for the rest of the ixtchacpul.’ Do you understand that word from our old language? It is—it is like—" Frustrated, he curtly waved for Professor Castillez to join them and supply the translation.

"Ixtchacpul?" repeated Castillez. "Oh yes—many long boats with armed men, moving together down a river.—ah! Armada!"

"An armada of spaceships from another planet!" Tom burst out excitedly. A fleet manned by space beings must have landed in the jungle centuries ago! Was it possible that these space people were so similar to humans that they had intermarried with people who had lived here originally, and were the ancestors of this particular tribe? He dismissed the thought as an impossibility. Yet it crept back upon him.

Tom asked the ahau if he could tell him any legends about his ancestors coming to Yucatan, or where the sacred stone came from. But Hu-Quetzal shook his head.

"I can not do it. There are so many old stories, mixed-up, with parts missing as from a jaguar’s bite. One thing I do not understand," he went on. "Why did my people long ago write with these signs, to tell those coming after of these things that happened? They are not like the picture writing the rest of the old firstfathers used."

"It was the space people themselves who left this message," Tom answered. "They may have wished that, if others of their kind came here, they would know what became of the first ones. The space people know that mathematics is the only exact ‘language’—a language which never changes, not even over thousands of years. I believe they wrote in these symbols so that people from any planet at any time could read and translate the message, even though the visitors could not speak or write any earth language."

The chief sighed and looked at Tom with great respect. "You are no doubt right, young one." It was plain that he was very much impressed by the young inventor’s knowledge. "It is said that once we Maya knew much of numbers and such things, and could tell the risings of the moon and the paths of the stars. So much has been lost, uuhma."

Tom’s brain was seething with excitement. What had happened to the space voyagers? Had part of the armada been wrecked during the jungle landing? Perhaps traces of their spacecraft could still be found!

Aloud, he said to Ahau Quetzal, "Perhaps your ancestors left other carved stones or relics. May we search the forest?"

The chief shrugged. "The government of Mexico has laws about such things. You must get their permission to do any digging."

"I am empowered to grant the necessary permission," stated Castillez, who had listened with growing astonishment. "I hereby do so."

"We will act with great care and respect!" Tom promised.

Meanwhile, Hutchcraft had been watching the muted conversation from a distance with great curiosity. As the ceremonial rock-slab was carried off to its sacred repository, he plied Bud, Chow, and Doc with questions, trying to find out the reasons for Tom’s interest in the sacred stone. But they politely, or less-than-politely, dodged his queries, thinking it wiser not to reveal any information of importance without Tom’s permission.

"Guess it’s time we started for the Queen," Tom said when he finally rejoined them. "The Professor says he is happy to lend his truck to us. It’s parked just off the road. Do you care to come along, Mr. Hutchcraft?"

"Thank you, but no—I might as well begin my work here," replied the linguist. "Watch out for our friend the jaguar!"

"If you don’t need my help, Tom, I’d prefer to stay behind too," Doc stated. "I have in my bag all I need to start off—" There was a sudden interruption. Led by Chief Quetzal, an odd delegation was approaching them.

"Jetz and super-jetz!" Bud exclaimed involuntarily, the only circumstance under which such an exclamation could ever be uttered.

The delegation consisted of five little Maya men, the same that had been introduced to the visitors before. But in place of their usual rough-cotton shorts, the small natives were now wearing ill-fitting city business suits!

One of the suits was bright blue serge, one was brown tweed, and the other three loud checkered patterns. All the clothes were so large for their wearers that the sleeves and trouser cuffs had been rolled back. Each man wore a felt hat pulled down over his ears.

Tom and his friends almost broke into laughter at the sight, but managed to stifle their mirth. Not so Wilson Hutchcraft, who giggled shrilly until Tom silenced him with a warning glance. The five little Mayas were obviously bursting with pride at their citified apparel.

"They look very impressive, ahau," said Doc Simpson cautiously. "But what is the occasion?"

"Have no fear," the ahau replied. "They are merely preparing for the journey."

"The journey?"

"Of course, to your far-north, to New York. These are the five of Huratlcuyon who are to accompany you in your great airplane."

"Oh boy," murmured Simpson. "Chief—Hu-Quetzal—there’s been a—you see—"

The ahau raised a hand. "I see. Of course. The long ride, in the back of the auto-truck will hurt-like-monkeys the garments they wear. But I will have them take them off and hold them in their laps. That will be well."

Doc shot a helpless look at Tom, and the young inventor stepped forward with a polite smile. "Chief Quetzal, we must apologize to you and to these good men. We did not explain well what we planned to do. My friend Dr. Simpson must first conduct some tests on many of your people. Then we ask you to allow him to make a selection himself—that is what he agreed to do, with Grandyke University."

Hu-Quetzal frowned but gave a single nod, slowly. "It is for you to say." He turned to the men and spoke to them in the village dialect. They appeared disappointed but immediately began to strip off their suits where they stood.

"We will save them carefully until they are needed," stated Quetzal.

Thanking him, Tom complimented the Indians on their fine appearance, and asked the chief where the clothes had come from. "We sent a runner to the city of Mérida to arrange for them," Hu-Quetzal explained. "We have many, many cousins who choose to live like the huaxixtlen, in cities. They help us."

Professor Castillez explained that the huaxixtlen were the Mexicans of European descent. "From haciendero, it is supposed. I fear the word is not always used as a compliment," he added wryly.

Tom glanced at his elaborate wristwatch. "We’d better grab our gear and get going."

Castillez’s old pickup truck proved to be battered, spattered, rusted—and big. As it rattled along the narrow, winding dirt road, so narrow that it sometimes seemed to merge with the lush jungle on either side, Tom, Bud, and Chow had plenty of room in the cab.

Yet comfort was lacking. "Brand my steam iron!" Chow grumbled. "I sure do wish we had a air-conditioner in this rattletrap."

"We do," replied Bud, pointing. "But it doesn’t work."

"Then that gives me another somethin’ t’ wish fer!"

It took the remainder of the morning to finally reach the Sky Queen, and by that time the travelers were thoroughly bedraggled and wet with perspiration. Chow’s wrist ached from fanning himself with his ten-gallon hat.

"Hey, strangers!" greeted Slim Davis, calling down from the belly hatch. "What’d you do, swim all the way?"

"Feels like it!" snorted Tom.

They climbed the ladder and immediately began to enjoy the comfort of the climate-controlled Flying Lab. The three took time for a cool shower and a cold lunch, then began to ferry the retroscope equipment into the truck bed, cushioning it with blankets and carefully tying down each component.

"What’s this thing run off of, Tom?" asked one of the crewmen assisting them, Bill Bennings. "Got a generator?"

"No," was the response. "The camera doesn’t take much more electricity than a TV set. One solar battery is more than enough for it."

After loading aboard the special tools and patching materials needed for repairing the grounded paraplane, Tom took a moment to make a quick radio call to his father at Swift Enterprises.

"Sounds like you’ve had a few adventures, as usual, son," Damon Swift chuckled. "But this business of the carved symbols—astonishing! Are you quite certain of what you saw? Such faint, weathered carvings can be subject to wishful thinking."

"Oh, I know," Tom replied. "That’s what the retroscope is here to handle. But remember, Chief Quetzal’s translation matched my own."

"Do you anticipate any difficulties in setting up the camera?"

"Not at all, Dad. But I have to admit, I’d feel a lot more confident if Hank or Arv were down here with us." Expert engineers and technicians, Hank Sterling and Arvid Hanson had remained behind at Enterprises to assist Mr. Swift preparing for an upcoming government-backed operation that demanded considerable time and technical planning. This vast and complicated project would involve work in a distant deep-sea environment.

Mr. Swift expressed regret that so much of the plant’s scientific and technical staff were tied up attending to these details. He also assured Tom that he would be on hand to greet the Mayan men when they arrived in Shopton and would escort them personally to Grandyke University.

Giving his love to family and friends, Tom signed off and returned to the truck. "I was hoping you’d dilly-dally a little longer, skipper," Bud pronounced, leaning on his elbow in the tattered front seat. "I wouldn’t mind a bit if we didn’t get moving until after sundown."

Tom laughed. "Maybe you wouldn’t, flyboy. But Chow would, wouldn’t you, pard?"

Chow looked puzzled. "Huh? Why’s that, boss?"

"Well, jungle bats that fly at night, for one thing. And then there’s that jaguar, creeping around in darkness. And—"

"Let’s get goin’!" the westerner gulped.

By the time Tom had signed off, the afternoon sky had darkened considerably. He had emerged from the Sky Queen to find a stiff wind blowing in from the southeast.

"What’s wrong, skipper?" Slim Davis asked, leaning on the truck windowsill as Tom gunned the engine. "You look worried."

"From the look of that sky, I think we’re in for a storm," Tom replied. "We can probably beat it, but it’ll be close."

The old truck rumbled off on its way back to Huratlcuyon. As the minutes dragged by, the wind rose and the palm fronds above began to writhe like snakes. Tom stopped briefly to pull a protective tarp of waterproof Tomasite plastic across the truck bed.

An hour later the storm had broken. A blanket of torrential rain swept down on the jungle, making visibility almost zero. The wind increased to gale force. Nervously watching through the cab windows, the boys and Chow saw the nearby trees bend under the smashing impact of the wind.

"Guess the wind just got its second wind!" gibed Bud. But his eyes were wide with tension as lightning slashed the darkened sky.

"Good night!" muttered Tom at the steering wheel, eyes squinting in the effort to make out the road. "We’re slipping and sliding on the mud. Better slow down."

Suddenly the truck began to shudder and move sideways, swerving into a fishtail.

"We’re bein’ pushed off th’ road by the wind!" Chow cried. "Tom, we’re gonna crash into the trees!"

INSTANTLY Tom’s right hand flew to the parking-brake lever, while his left hand smoothly twisted the wheel, steering into the skid so as not to worsen it. His skillful maneuver kept the truck from nosing into a tree trunk, but he couldn’t prevent its thudding sideways against a mass of fallen branches.

"Mebbe we oughta abandon ship—’er somethin’!" rumbled Chow in fear.

"Too dangerous in this storm,’ Tom replied tersely. "But maybe I can hold us off from crashing any further into the forest." As the groaning wind whipped about the truck, Tom inched it forward onto a mat of thick leaves and intertwined branches. He knew this would provide them a bit of wheel-traction and a fair fight against the wind.

"Whew!" Bud mopped his forehead. "That’s what I call too close for comfort! I had visions of us plowing into that big trunk and the whole tree keeling over on us!"

The roar of the hurricane winds outside and the clattering impact of the rain against the truck made it almost impossible for Tom and his companions to hear each other’s voices.

They slowly became used to the lightning that seemed to flash unnervingly close. Then they flinched back as an even more dazzling light blinded them!

"We been hit!" Chow bellowed.

To his astonishment, Tom broke out laughing. "Calm down, cowpoke! Look!—it’s just the sun breaking through."

A crack of burning yellow-white had appeared in the charcoal sky, near the western horizon. The squall seemed to be breaking apart as fast as it had appeared.

"Wa-aal, lookit them clouds," exclaimed Chow in calmer tones. "Scurryin’ along like a sky stampede!"

In minutes the storm was entirely over, the drenched, dripping jungle twinkling in the late-afternoon light.

"Guess we can stow the water-wings," Bud declared. "Can we get under way again?"

"Maybe," responded the young inventor. "These tires are pretty big and broad, and the axles are fairly high off the ground. Let’s scope out the road." Gunning the engine, he eased them forward in the direction of the roadway, expecting to find it running like a river.

But when the truck emerged through the brush, they found that the jungle had unveiled another surprise. The road was muddy and puddled, but almost completely visible!

"Now howd’ya figure that?" Bud asked, scratching his head. "Where’d all the water go?"

Tom thought the matter over for a moment, glancing at the map of the area. "It’s interesting, isn’t it? This little road isn’t just gouged into the ground by occasional traffic. It seems to be very slightly elevated. The water just runs right off."

"Guess someone really thought her through," ventured Chow. "Good news fer us."

"I know what you’re thinking, genius boy," Bud said. "You’re wondering if somebody actually constructed the road—the old Mayas, maybe."

Tom nodded. "That’s right. It’s disguised by several centuries worth of mud, rotting leaves, pebbles—all sorts of random junk; but go down far enough and I’ll bet you’d find some kind of stonework."

"In other words, a paved highway!"

"That’s what I’m thinking."

Chow raised an objection. "That’s all right nice, but yew sure don’t go t’ the trouble to make a highway out in the middle o’ nowhere, less’n it goes someplace. That little ole village don’t strike me as worth it."

"I agree," said Tom. "I doubt the village itself, the actual huts, is even a hundred years old. But it may have been the latest in a long line of settlements at, or near, the same spot. Look at the map." He spread it across their laps. "This broken line is our poor little road. Go on past where the Queen is and eventually it merges with the big road that leads to Polyuc. We don’t know what happened to that end of the road, of course, but there are plenty of ancient ceremonial centers and ruins in the Polyuc area."

"Okay," Bud conceded. "What about the other end?"

Tom moved his pointing finger along the line of the road. "It runs along fairly straight—then here, a few miles ahead, it curves off toward Huratlcuyon all of a sudden. After it passes the village, it runs on for just a couple thousand feet, looks like, and just stops."

"Like I said," remarked Chow, "—middle o’ nowhere!"

"Sure, that’s what it looks like now, Chow," Tom agreed. "But what might’ve been there a thousand years ago?"

Bud’s eyes gleamed. "Maybe a wrecked super-spaceship or two?"

Tom chuckled. "I’d settle for just one! What I really have in mind is something like a carved monument or a temple, something commemorating the strangers from the sky. We’ll see!"

The tired truck finally pulled in to Huratlcuyon at dusk. Professor Castillez came out to greet them, shaking Tom’s hand in relief. "When the storm hit, we were very worried; especially when we contacted your man in the airplane and were told you had left hours before. The medico, Simpson, wanted to go the length of the road on foot to search for you, but Hutchcraft and I convinced him it would be too dangerous."

Doc now came trotting up and gave each of the travelers a bear hug. "And while you boys were out wallowing around, I was able to make some real progress identifying our Grandyke prospects. I’ve narrowed it down to eleven men."

"I have some news too," Tom said. He briefly related his theory concerning the old roadway, repeating it again as Chief Quetzal arrived.

"The great-path is very old," commented the ahau. "More than that, I do not know."

"Have you any stories of stone monuments once standing in this area, or ruined buildings?" Tom asked. "Sometimes such knowledge is passed along, father to son."

"I say again, Tom-Swift, I do not know." Hu-Quetzal suddenly turned and strode away.

Chow, a good judge of character, had an opinion. "That feller’s hidin’ something, boss. He knows a peck more’n he’s sayin’—which ain’t so hard, since he ain’t sayin’ nothin’ no-how!"

Tom nodded, frowning, but decided to say nothing himself.

The young inventor felt it best to stow the retroscope equipment and patching materials in Chief Quetzal’s hut for the night, where they would be protected, safe under the watchful eyes of the Americans. This they did piece by piece with great care, finishing in the glow of the village cookfires.

"Well! What have we here?"

Tom turned and found Wilson Hutchcraft languidly regarding him from one of the doorways. "How are you, Mr. Hutchcraft?"

The philologist-archaeologist ignored the question and stepped into the hut, glancing over the assemblage of electronics equipment with a vaguely critical air. "No doubt this is your televised time machine, hmm?" Tom confirmed the guess, and Hutchcraft continued, "Quite a tangle of electrical spaghetti, but I suppose that’s the kind of thing you technician-sorts like. I find hands-on investigation so much more rewarding."

Tom tried to conceal his growing irritation. "I’m sure it is, in its way. But my invention doesn’t replace that kind of work. It makes it easier and more productive."

"If it should happen to work, hmm?" Hutchcraft sank down on Doc Simpson’s vacant hammock and wiped his forehead. "And just how does it work? How do you take pictures of the past? As the poet said, The past, passed, dead, ever fled, beyond recall."

"I’m not sure I’d expect a poet to understand it," Tom said with a smile. "But I’ll be glad to explain the general idea."

The retroscope camera was based on two earlier achievements of the Swifts. One was Tom’s discovery of a hitherto unknown radiation, the spectron rays or "space-waves," that selectively interacted with the nuclear configurations at the core of all matter. This had led to the invention of the Swift Spectroscope and the force-ray repelatron used in Tom’s latest spaceship.

The new camera also made use of certain scanning features originally developed by Tom’s celebrated great-grandfather for his so-called television detector, further elaborated for use in Tom’s Eye-Spy camera, as Bud had nicknamed it. This remarkable device could take video-type pictures through a wall or other solid object.

"I call my invention a retroscope," Tom went on, "because ‘retro’ means ‘back’ or ‘backward’—as in retro-rocket—and the camera is suppose to allow us to ‘see back’ how a carved object looked originally, hundreds or even thousands of years in the past."

"A very sensible name, at any rate," Hutchcraft remarked dryly. "But how is this miracle to be accomplished?"

Tom began to gesture as if drawing diagrams in the air, a habit that seemed to help him think. "Think of a carved stone or other such surface. As I’m sure you know, any rock may undergo radioactive aging as its natural elements break down and become other elements. That happens all through the rock, and can be used for dating the materials. But the layers nearer the surface are more exposed to cosmic radiation from the outside, which is always streaming down from space."

"Mm-hmm," said Hutchcraft. "A carved surface means that different layers of rock are exposed at one time."

"Exactly," said Tom. "For instance, if you carve a gouge in the rock, the cosmic radiation would penetrate deeper at that point than it would at an uncarved part of the rock. Therefore, as the cosmic rays penetrate a slight ways into the solid material, a sort of pattern is created inside the rock that follows the in-and-out depth pattern of the carvings on its surface."

"Wait a minute!" Hutchcraft snapped his fingers in unimpressed sarcasm. "I think I get it. By measuring the pattern of penetration all through the rock, you can put together a picture of what the carving looked like before it was worn away."

"That’s right, Mr. Hutchcraft," Tom said mildly. "Of course, the original cosmic rays are long gone, either absorbed or reflected back."

"Then what remains to be measured?"

"I’m getting to that. My device makes use of the natural magnetism in the rock to—"

The archeologist held up an imperious hand. "Magnetism? You expect to find these inscriptions carved into magnetic rock?"

"Not at all. Like most people, you may be under the impression that natural magnetism is only to be found in certain kinds of rock—lodestones, as they’re called. That’s true enough if you’re trying to produce a useful magnet, but it isn’t the whole story. All atoms, of any kind of material, possess magnetic properties; it’s a consequence of their internal configuration of electrical charges. They can be diamagnetic, weakly repelled by a magnetic field; paramagnetic, weakly attracted; or ferromagnetic, which produces the strong response we associate with standard magnets."

"I understand," said Hutchcraft impatiently.

"Ordinary rock, however pure, normally has traces of differing substances showing the whole range of magnetic properties. Most of these particles lie every which way, randomly, but a percentage magnetically arrange themselves with parallel or non-parallel orientations, which can be ‘flipped’ by a nanosecond’s exposure to a cosmic ray."

"Then to anticipate you," the archaeologist interrupted, "I would suppose you to have a devilishly ingenious method that allows you to ‘read’ the general layout of these flipped particles. And from that you can derive the corresponding pattern of cosmic-ray penetration. And there’s your picture. That it?"

Tom grinned. "Simple, isn’t it? Now, my camera here has two detectors. One scans the whole surface of the rock to probe out areas—called domains—of shared magnetic-dipole orientation; this gives us a baseline for comparison. The other uses a spectronic scanning beam to map out the quantized—"

Hutchcraft suddenly slid onto his feet and stretched. "All very interesting, and now my curiosity is satisfied—in fact, saturated. I believe I’ll have a bite to eat." He turned his back on the young inventor and ambled out of the hut, leaving Tom with a disbelieving grin at the older man’s self-centered abruptness.

Early the next day, before the humidity became too steamy, Tom trudged over to the grounded paraplane carrying the patching kit, Bud and Chow following. Wilson Hutchcraft, invited to watch as a courtesy, remained behind, saying he saw no reason to waste his energy unnecessarily.

"Wa-aal, I’ll be a horned toad!" Chow grumbled under his breath.

Arriving at the paraplane, Chow cast a critical eye on the rip in the liftbag. "Don’t look all that long t’ me, boss."

Tom gave a wry smile. "It’s enough. Unfortunately the arrow struck right along one of the transifoil strips, and the bag tore a ways along the seam. Seems I didn’t ‘weld’ the pieces together as durably as I thought."

"Which reminds me, genius boy," Bud remarked, "we still have no clue as to who shot that millionaire-arrow."

"Got me an inkling," muttered Chow, eyes narrowed.

Tom knew what he was thinking. "So far, Hutchcraft hasn’t been murderous," he pointed out; "just obnoxious." But Tom’s silent thoughts continued further: As an archaeologist, he sure was in a good position to come up with that sort of old-style Mayan arrowhead!

The rip was easily repaired to Tom’s satisfaction, and he tested the seal with a small hand-held instrument.

"Looks okay," pronounced the youth. "Let’s take ’er up—I told Slim I’d make a run over the Sky Queen and dip my wings. I’ll land the plane as close to the village as possible." The three climbed aboard.

Tom took his place at the controls, gave them a cursory check, and opened the release valve for the reserve helium tank. Tom waited for the liftbag to expand and become rigid as the transifoil strips responded automatically to the rising pressure of the helium gas within. But nothing happened! The liftbag remained limp and folded.

"What’s wrong?" Bud asked.

"Don’t know," Tom replied in a puzzled voice. "Maybe a loose connection in the transifoil power feed." When the instruments had eliminated this possibility, Tom said: "I’d better check the tank."

A moment later, after inspecting the secondary pressure gauge built into the reserve tank itself, he turned a grave face to his companions.

"The tank’s empty!" Tom reported.

BUD sprang out of his seat and scrambled aft to join the young inventor. "You mean the liquid helium leaked out?" he asked in alarm.

"It leaked out all right," Tom replied grimly. "Look here, flyboy. The loading cock is wide open."

"Good grief! How did that happen?"

Tom gave a worried shrug. "Maybe I got careless and popped it accidentally from the control board—maybe. But frankly, I don’t remember even touching the lever before we left the ship. How about you two?"

Both Bud and Chow denied knowing anything about it. Chow, who was dripping with sweat and fanning himself with a sombrero given him by Professor Castillez, added, "Mebbe it’s this broilin’ hot weather. Must’ve made the helium swell up an’ bust out—like th’ vapor-lock on a car."

Tom shook his head. "The tank insulation protects it from the heat. And besides, the helium wouldn’t expand enough to force the loading cock!" He wondered uneasily if someone might have tampered with the plane during their absence, and said so.

Bud looked dangerous. "Easy bet as to who we’re all thinking about!"

"We’d better check out the whole ship to make sure nothing else is wrong," Tom decided.

With Bud’s help, Tom hastily checked the jet engines, landing gear, instruments, and other parts. But the paraplane showed no other sign of sabotage.

"Okey-doke then. Now what?" Chow asked.

Tom shrugged. "Looks as if we’ll have to drive back to the Sky Queen and pick up another full tank."

Chow looked pained at this announcement. "No offense, boss, but mebbe I’ll jest stay behind this time. Still got those recipes t’ collect."

"What about the plane?" demanded Bud. "You’re not going to abandon it here, are you?"

Tom hesitated, turning the matter over rapidly in his mind. "Look," he said to Bud and Chow, "now that I know the way, I’ll drive back to the Queen alone this afternoon, and spend the night. I’ll use the rest of the morning to rig up an alarm system for the paraplane, the same sort of thing we have around the house in Shopton, but with a remote beeper. Would you two mind keeping an ear on it until I get back?"

Both agreed readily.

Climbing back aboard the paraplane, Tom made radio contact with the Sky Queen.

"So how come you’re not upstairs, as you planned?" Slim Davis asked. "Anything wrong?"

Tom reported the mysterious loss of helium from the plane’s tanks. "We’ll have to leave the paraplane here for the time being," he concluded. "I’ll see you guys by sundown."

"Fine place you picked to run out of gas!" Slim gibed.

"Tell me about it! But don’t sell us short—I’ll get ’er fixed. I mean, the future of the airship is at stake!" Tom joked.

The drive back to the Flying Lab was long, hot, and uneventful. Arriving at twilight, Tom had a satisfying supper aboard, then contacted Huratlcuyon, transmitting to Professor Castillez’s short-wave radio.

"All is quiet here, Tom," reported Castillez. "I have been half-listening for the buzz of your alarm-monitor, but there is nothing so far."

"Good," commented Tom. "Maybe we’ll all manage a good night’s sleep tonight."

First, however, the young inventor felt moved to work on a technical challenge that had occupied his mind during the long drive from the village. He headed for his electronics work-module, one of the small compartments on deck two. A crewman, Dick Folsom, stopped him on his way for a moment of conversation.

"Cooking up something new in your mini-lab, chief?"

"Not exactly new, but definitely smaller," was the reply. "At present the baseline-detector apparatus sits as a separate unit—another big box to lug around, along with the camera console itself and the other parts. I have a notion I can miniaturize that phase of the process and bolt the equipment right on to the main camera body."

"Boy, you’ve got a job on your hands, skipper." Dick frowned as he examined with a professional eye a sketch Tom had made in his notebook. "Neat concept. But my guess is that redesigning your camera ‘eyes’ will take at least a week’s work back at the plant."

"Can’t wait that long—I need the retroscope now, while we’re here in Yucatan. I’m a pretty impatient guy!" Tom ran his fingers through his ragged blond crewcut. "Maybe I’m taking a long shot, but I’m going to try turning out a new rig right here in the Flying Lab."

"Tall order, Tom!" Dick whistled. "But you can do it if anyone can. I’d better clear out, so you can work undisturbed."

Dick Folsom had hardly walked away when Tom plunged into his problem full-throttle. He whipped out a sophisticated calculator and began applying its results to a circuit diagram taking shape on his design flatscreen.

"One thing’s certain," Tom murmured to himself. "To get fine detail in the picture and still keep the rig down to portable size, I’ll have to miniaturize the whole scanning apparatus. Maybe I can cut a few corners by a parallel-processing gimmick…"

Hours went by. Tom’s desk-workbench became littered with scribbled equations, exclamation-marked notes, and sketches of parts layouts. Finally he broke off long enough to buzz the galley over the intercom and ask for food. Slim Davis responded. "You still hard at it, Tom?" he asked in amused surprise. "I just dropped by for an after-midnight snack."

"After midnight?" Tom laughed out loud at himself. "And I was planning a solid night’s sleep!"

But he was hot on the trail and couldn’t bear to stop. By two o’clock Tom had begun to rig up the new miniaturized detector component for testing, even though he was still not certain he had licked the problems completely. Some time later he glanced at his wristwatch.

"Ten after four!" The young inventor gave a whistle. "What a skullcracker this turned out to be! Dick sure wasn’t kidding when he guessed it would take a week’s work."

Yawning wide and leaning back on his work stool, Tom stretched his cramped limbs. Sure wish Bud and Chow were here, he thought wistfully. Bud’s breezy quips and Chow’s many puzzled questions not only gave Tom a lift, but often played a part in giving him a new insight into whatever problem he was tackling.

Soon he was back at work assembling a spiderweb-like mass of tiny micro-components—transistors, diodes, triodes, anodes, magnetodes, and other solid-state odes to modern genius. But presently Tom’s head slumped toward the workbench and he drowsed off from sheer exhaustion, dreaming of numbers.

Meanwhile, Bud Barclay and Chow were turning and tossing in their hammocks back in the Mayan village. A horde of tiny insects buzzed maddeningly outside their mosquito netting.

Presently Bud whispered, "Hey, Chow! You awake?"

"I sure am," the cook grunted softly, careful not to disturb Doc Simpson. He managed to lean over close to Bud’s ear, wrapped in his netting. "These pesky flyin’ buzzsaws are drivin’ me plumb loco, let alone all them jungle noises out there. I’m purt near sure I heard that jaguar!"

"You suppose the paraplane’s safe?"

Chow raised up on one shoulder. The moonlight shining in through the door of the hut showed a worried look on his weather-beaten face. He whispered in reply, "It better be if we’re ever aimin’ to get out o’ this jungle. Why? You figger it ain’t?"

"I don’t know what to figure," Bud replied restlessly. Throwing off the netting, he got onto his feet and padded softly to the open hut door. Suddenly, as if alarmed, he beckoned for Chow to join him.

"Whatsamatter, Buddy Boy?" demanded the Texan as they both stepped out into the open. "Didn’t hear that alarm-beeper go off."

"It didn’t," Bud hissed, "but look over there!"

"Don’t see nothin’."

"That’s the point, Chow. Where’s Hutchcraft?"

The Bostonian’s sleeping bag was zippered and empty!

"Aw nuts!" Chow groaned. "That big-brained sidewinder’s prob’ly off messin’ with somethin’ else on Tom’s balloon-plane."

"Absolutely!" Bud grated. "With Tom gone, he must figure it’s a great night to come back and pull another trick!"

The cook exclaimed in muted alarm. "Brand my britches, now you got me worried! Come on, Buddy Boy. You an’ me better hop out there an’ take a look-see—jest to make sure!"

As if to emphasize the point, the monitor clipped to Bud’s elastic waistband suddenly gave forth a chirp of warning. Someone had tripped the plane’s alarm system!

Pulling on some clothes to keep the darting night insects at bay, the pair tiptoed out of the hut and made their way through the sleeping village and along the half-hidden jungle path to the paraplane site. As they passed the outer fringe of brush, stepping into the deeply-shadowed clearing, Bud suddenly grabbed Chow’s arm. Chow gave a hoarse croak and froze in his tracks. "B-B-Bud!" he gasped. "D’you see what I see?"

"I sure do!"

The two could hardly believe their eyes. A huge hulking figure, which looked at least eight feet tall, was moving furtively near the nose of the paraplane! Suddenly the silhouette froze, as if listening, then darted off with surprising nimbleness into the leafy underbrush.

"What in tarnation was it?" Chow gulped. "A g’rilla?"

"Not around here." Gathering his wits, Bud spurted forward. "Come on! Let’s see where it went, whatever it is! I want a closer look!"

Together, they reached the plane and plunged into the underbrush on the far side where the giant form had disappeared.

"Leapin’ rattlesnakes!" Chow quavered, as they groped about among the tangled creepers and head-high jungle growth. "It’s so dark in here I can’t tell which is you an’ which is me!"

His nervous wisecrack seemed hardly an exaggeration. Scarcely a ray of starlight pierced the darkness, now that they had left the beaten trail. The leafy canopy above them was too densely overgrown.

"Guess you’re right," Bud agreed. "We don’t stand much chance of finding him—or it—now."

Giving up the search, they backtracked to the paraplane and Bud, an expert pilot, made a quick check of it. Everything seemed to be in order.

"What do we do now, pardner?" Chow asked.

Bud shrugged helplessly. "Not much we can do, I guess. Whatever that was we saw, I have a hunch it won’t risk a return visit—not tonight, anyhow."

"An’ I got m’self a hunch o’ my own," declared Chow. "What-so-ever that spooky giant turns out to be, my hunch connects it up to a Hutch—meanin’ that there Mr. Fancy-Pants hisself, Hutchcraft!"

AS THE sun mounted high the next morning, Bud made a call to the Flying Lab, anxious to tell Tom about the night’s hulking phantom. The skyship’s flight engineer, Jack Murray, answered the signal. "Our ol’ junior genius is fast asleep, sleeping in," he reported with a half-chuckle. "Had one of his late-night inventing sprees. Shall I wake him?"

"No, that’s okay," Bud replied. "It’ll keep till he gets here this afternoon."

At breakfast, which Hutchcraft condescended to join, Bud asked the Bostonian about his mysterious absence during the night.

"I went to get some insect repellent out of my gear," Hutchcraft replied calmly. "I have my knapsack stowed in one of the huts. For that matter," he added, "what were you two doing up wandering around?"

Bud told of their visit to the plane and the looming figure they had sighted. Hutchcraft could throw no light on the mystery. "Sounds to me as if you both were having a nightmare," he remarked with a needling chuckle.

Chow snorted angrily, but said nothing.

Shortly after two, Bud, helping Doc with his examinations, heard the distinctive sound of Castillez’s truck pulling to a stop out on the dirt roadway. He trotted over to help Tom unload and the two chums exchanged greetings.

"Wait’ll you hear this one, skipper! You won’t believe it!" exclaimed Bud. As the youths walked back to the village carrying the replacement helium tank between them, he proceeded to describe the strange encounter next to the paraplane, concluding with: "When we got back to the village, Hutchcraft was already snug in his bag and pretending to snore. Naturally, this morning he made an excuse. He claims not to know anything about the giant."

Tom was staring at Bud wide-eyed as they lowered the tank to the ground. "A giant!" he gasped, then broke into a wry chuckle to show he was only ribbing his pal. "Are you sure you two weren’t seeing things?"

"I said you wouldn’t believe me," Bud retorted. "But it’s no joke."

Professor Castillez had ambled up during the discussion, and Tom noticed that Chief Quetzal, standing in silent dignity not far off with several of the village men, had also heard the story.

One of the men cautiously approached them. "You Swifts, what you see, I see." He spoke very haltingly and obviously knew little English.

Tom asked him what he had seen. "What I see—" But the man seemed unable to find the words. After a few attempts, he said a few phrases in his own language, with some Spanish mixed in.

"This man’s name is Xuy," stated Castillez. "He is the head of the food and provisions ministry, one might say. He has seen the what he calls the Big Moon Shadow twice now." The Professor asked Xuy some questions in Mayan-Spanish. "He says others in the village have seen him. They call him the cave man—the giant who can crush a jaguar with his bare hands!"

The man stared fearfully at the two Americans and gave a vigorous nod.

Bud and Tom looked at each other in astonishment. A giant in the Yucatan jungle? A cave man powerful enough to kill jaguars with his bare hands? It sounded weird! Yet there was certainly some kind of giant lurking out in the brush—Bud had seen him with his own eyes, and despite his joking skepticism Tom believed his friend without question.

The young inventor now approached Hu-Quetzal, who gazed at him impassively. "Ahau, have you seen the giant yourself?’’ Tom asked Quetzal.

"Tell us more, please," Bud urged the chief. "Who is this giant? Where did he come from?"

Quetzal looked at the two white men as if he failed to understand. When Bud repeated his questions, the chief shrugged and mumbled something in the Mayan tongue and pointedly stepped away from them.

Tom and Bud rejoined Professor Castillez. "Alas, I fear this is an occasion when he does not want to understand you," the ethnologist said with a slight shrug. "These people regard such things as intimate matters—private and sensitive. Despite the rules of hospitality, one does not discuss them readily with strangers."

"It seems you’re right," Tom agreed. "I’d better change the subject." The ahau was now standing next to his hut some distance away. The chief’s unblinking stare made both Americans feel somewhat uncomfortable. However, when they approached again with respectful nods he seemed as friendly as ever. When Tom spoke of his plan to dig for relics near the end of the ancient road, Quetzal said approvingly:

"You are a very wise young man. Perhaps you will find another stone carved by my people’s ancestors—or the others."

As the chief walked away and Tom returned to Bud and Castillez, Bud wore a puzzled frown. "What do you make of it?"

Tom shrugged. "He may be embarrassed because his whole village is afraid of the giant."

"I mean, what do you make of that stuff the other guy told us—the cave man business, and crushing jaguars?"

"It beats me," the scientist-inventor replied with a chuckle. "Another thing. If that’s the guy who sabotaged our helium tank, what’s his game?"

Castillez made a suggestion, thoughtfully. "It is possible he is only curious about the plane. If perhaps he’s lived his life here, in the jungle, he may never have seen an airplane except distantly in the sky."

After stowing the helium tank in the safety of Chief Quetzal’s hut, Tom hunted up Doc Simpson, finding him behind a hut at the further side of the village. Chow, who had taken Bud’s place, was helping him examine a half-dozen of the men. After greeting Tom, Doc discussed the progress he had made. "I will definitely be taking five of these six men back to the States. They’re really amazing subjects, Tom."

He told Tom that their basal metabolism—the rate at which their bodies used energy—was five to eight percent higher than that of the average North American. "Here’s another interesting feature," he added, as he held an instrument up to one man’s eyes to allow Tom to see. "Notice this trace of a fold of flesh at the inner corner of each eye, called the epicanthic fold. When large, it’s what gives Asians their characteristic facial appearance. In fact, all these people in this village show unusually strong chromosomal indicators connecting them to Asian ancestors many generations back."

"That seems to bear out the theory that Indian tribes crossed over to this continent from Asia back when Alaska was joined to Siberia by a land bridge," Tom commented.

"Yes, or perhaps travelled across the Pacific by boat."

As Doc proceeded to give the Mayas a more detailed examination, Tom left him and returned to the parked truck. He was anxious to finish assembling the retroscope and to try out the new-version scanner he had brought back from the Sky Queen.

With Bud’s help, the improved camera soon stood completed in the afternoon sunlight in front of Chief Quetzal’s hut. Most of the village seemed to have quietly gathered around, respectfully standing back and giving Tom a space in which to work. Even the stolid chief himself seemed fascinated and somewhat awed.

"It looks complicated, ahau, but the basic principle is fairly simple," Tom said to him with a smile.

The main chassis of the retroscope was flat, shallow, and rectangular, like an oversized shirt box. It was clamped inside an X-shaped frame of support struts, which were in turn connected to a low wheeled platform on the ground. A metal cylinder extended from the front of the camera, widening at the end to a disk that was slightly concave on the side that would face the carved surfaces. Fastened to the top of the console was a big, transparent dome, looking like an embedded half-bubble.

The entire camera apparatus was connected to two other units. A flexible hose ran from the back of the camera chassis to a collection of pumps and compressors with a small, compact tank—like a thermos bottle—at its center. This unit had a valve wheel on top. In addition several long, thick wire leads ran back and forth from the camera to a fairly bulky box-shaped console that stood separately a few feet away.

He walked about the apparatus, touching its various parts as he spoke. "This cylinder is the main scanning mechanism, by which we detect the underlying patterns. The disk up front is the emitter-receiver for the scanning beam itself. These long tubes along the length of the camera chassis are new sensor units that I just designed; they’ll establish the initial baseline reading for whatever we’re scanning." He moved over to the box-shaped unit. "In here is the battery power source, as well as the primary processing computer. It has to be rather large, as it does most of the work."

"What about that there, boss?" asked Chow, who had joined the crowd along with Doc Simpson and Wilson Hutchcraft. "Looks like a propane tank fer one o’ them barbecues."

"It’s liquid helium, Chow."

"Hunh? You gonna make this here camera float in th’ air like your pair-o-plane?"

Tom laughed pleasantly. "It’d sure make it easier to move around! But seriously, liquid helium is so cold it diminishes the ‘noise’ of molecular motion in our ultra-sensitive detector circuits."

Now Bud spoke. "Genius boy, what’s with the dome on top? It’s new, isn’t it?"

Tom nodded. "Another part of my miniaturization craze. It contains stroboscopic mini-lasers which allow me to eyeball, directly, some crucial aspects of helium flow turbulence. Doing it this way allows me to get rid of a bunch of gauges and meters, and, surprisingly, it’s just as accurate."

"And where do you see the picture, Tom-Swift?" asked Ahau Quetzal. "I thought perhaps a television or cinema film."

The young inventor opened up a small rectangular panel on the side of the camera case which swung open on a hinge. Beneath it was a small screen, slightly recessed into the chassis; and there was another screen on the inner surface of the panel itself. "These are our viewing screens," he explained. "The one on the cover-panel shows the outer view of the rock or carving, as visible to the eye, while the other one shows the image constructed by the computer from the scanning data."

"It’s fantastic," murmured Doc. Even Hutchcraft seemed momentarily impressed.

Hu-Quetzal asked when Tom would begin using the retroscope on actual stones.

"Right now, if we can find any old Mayan stone carvings around here. I’d like to work out all the bugs before using it on your sacred ceremonial stone."

"That is best," the chief said with grave approval.

Tom, Bud, and the other visitors to Huratlcuyon now fanned out to search for marked stones. "Better not stray too far from the clearing," Tom warned. He had the lurking giant in mind.

Minutes later, Doc yelled, "Think I’ve found one!" and the others hurried to join him. He pointed to a round, weather-beaten stone lying almost hidden in the tall grass to the south of the huts. It seemed to bear faint carvings.

"Let’s see if we can lift it," Tom said, bending down to pry the stone loose.

The next instant he recoiled with a startled gasp. A green iguana, almost six feet long from tip to tail, had suddenly raised its ugly head from the undergrowth! Rearing up on its hind legs with jaws open, the reptile lunged as if to rake Tom’s face with its claws.

"Good grief!" Tom gulped, jumping back hastily in the nick of time,

"You really scared that poor lizard, Tom," Doc Simpson teased. "That’s why she went for you. Iguanas really aren’t as fierce as they look."

"Just the same, I won’t try taking this one for a pet," Tom said with a rueful chuckle.

"I made a pet of one once," Hutchcraft remarked. "Died on me, though."

It took the efforts of four men, none of them Hutchcraft, to dislodge the stone and lug it back to the retroscope.

Tom quickly aimed his camera, flicked a power switch, and began tuning several dials. "These markings look fairly recent—not more than a thousand years old," he remarked jokingly, "but it’s good enough for a test."

The others watched the screen over Tom’s shoulder as he carefully manipulated the control knobs, and a faint image leapt into view.

"Brand my spurs!" gulped Chow. "It’s workin’, boss!"

But Tom’s forehead bore a deep furrow of disappointment. The picture produced by the retroscope was a mere blur! No distinct figures could be detected amidst the visual fog.

Tom made numerous adjustments without success. His face filled with dismay.

Was his new invention a failure?

"ANY idea what’s wrong?" Professor Castillez asked in a sympathetic tone.

"Not yet. I feel like giving it a kick, like an old TV set." The young inventor unscrewed the rear panel of the camera’s main unit. "Have to check a few of these circuits first."

Bud and the others watched as he probed deftly among the maze of microelectronic parts. Using an oscilloscope and several other testing devices, Tom made a quick check of the reproducer component, then the "brain," and finally each part of the scanning apparatus.

"What’s the verdict, trouble shooter?" Bud asked, as the young scientist-inventor finished examining the setup.

"Everything checks out," Tom said gloomily, "so the fault must be in my design. I have a hunch it’s the scanner. Apparently it doesn’t ‘see’ the stone in enough detail for the reproducer to form a clear picture."

Bud was almost as dismayed as Tom, but tried to cheer his pal. "You’ll work it out, skipper—probably in the middle of the night!"

Tom gave a wry smile of thanks. "At any rate, at least one part of the retroscope is working just fine—the master time dial."

"What’s that?" inquired Doc.

"A separate function of the camera which uses various kinds of magnetization and radioactive-decomposition data to calculate when a carved surface was first exposed. Turns out in this case that it’s four baktuns old."

Bud’s brow puckered into a frown. "Four which?"

"Ya picked my brain, Buddy Boy!" Chow said.

"Four baktuns." Tom chuckled. "Dad sent some books on Mayan culture with me, and I’ve been reading up on their calendar and system of numbers. A baktun is four hundred years. The actual date, if it were carved on the stone, would be—let me see, 8.14.0.0.0 7 Ahau 3 Xul, which would be September first, A.D. 317, by our calendar."

"Wow! Over sixteen hundred years old!" Bud gave a whistle.

"Our course, your estimation ignores the intercalary ‘bad-luck’ days, as they were regarded," was Hutchcraft's supercilious comment. "But close enough, I suppose."

Bud gave the man a look of irritation. "That’s plenty ancient for me! But what if the inscribed date turns out to be different from what your time dial reads?"

"Then I’ll assume the retroscope is at fault," Tom responded. "The old Mayas just didn’t make mistakes when it came to dates. By means of astronomy they were able to figure out the length of a solar year right on the button. And they were wizards with numbers."

Tom went on to explain how the Mayas had developed two kinds of numerical notations. One, using a system of bars and dots, was simpler and easier to figure out than Roman numerals. The other, using pictures of human heads to represent the numbers from one to thirteen and also zero, was much like our present-day Arabic numerals.

"What’s even more amazing," Tom told Bud as the others listened, "the old Mayas were first to develop an accurate calendar and to reckon time from a fixed date. They were able to figure out the length of a year so closely that their calendar was actually more accurate than the one Americans were using at the time George Washington was born."

"Must’ve been a bunch o’ smart cookies,’’ Chow said, impressed.

"It’s strange how such a great civilization as theirs could decline," mused Doc Simpson. "I’ve read that many of their cities and ceremonial sites were abandoned abruptly, almost overnight."

"Yes, it is true," nodded Hu-Quetzal.

"As to that," began Hutchcraft in a lecturing tone, "several theorists have suggested—"

Tom pretended not to notice. "You must read this book, Doc. Right now I’d better stop talking and pack down the retroscope for the night. Then—next order of business—installing the new helium tank in the paraplane."

Tom and Bud efficiently completed the stowing of the retroscope. Leaving the village, the two set off down the jungle path again carrying the helium tank, Chow following closely with many a nervous glance at the shadowed underbrush. When they reached the paraplane, Bud made another quick check of the craft, both inside and out. "Doesn’t look like anybody’s fooled around with it, Tom," he declared.

Tom nodded, wiping the perspiration from his brow. "That’s good news, at any—"

"Pssst!" Chow interrupted with a hiss of alarm. As the youths looked up at their friend, startled, the westerner whispered. "We’re bein’ watched! I seen eyes back in those shadows over there—an’ I mean big ones, an’ high up, too!"

Tom tried to undertake a subtle glance, but it was too late to hold back Bud. The dark-haired pilot impulsively plunged among the trees but had gone only a short distance when he stopped short with a startled cry.

"The giant!" Bud gulped, as a huge, hairy, half-naked white man loomed out of the tangled shrubbery, blocking the boy’s path. He was clad only in a loincloth, with sandals made of palm fibers. His long flowing hair hung down to his shoulders.

Seeing Bud’s horrified look, the man threw back his head and gave a deep booming laugh. As Bud stepped back, seeking to dodge out of his way, the giant reached out and grabbed up the husky young flier as if he were a baby. Grabbing his collar and supporting him on the palm of one huge hand, the eight-footer spun Bud’s athletic six feet around him with no difficulty at all.

"Now you are the slave of the King of the Jungle!" the man roared in English.

"Cut it out! Let me down!" Bud yelled. He squirmed frantically in an effort to free himself, but the giant clutched him in a viselike grip!

"Okay man, you asked for it!" Bud gritted. Twining both hands in the giant’s flowing locks, Bud yanked the man’s hair until he yelped with pain. He promptly loosened his hold and Bud jumped to the ground.

To Bud’s surprise, the giant seemed to bear him no ill will over the hair-pulling. Instead, he gave another of his bellowing laughs. "Nice going, young fellow!" the giant said, patting Bud on the shoulder with a ham-sized hand. "I respect anyone as brave as you! Weren’t frightened a bit, were you?"

At that moment Tom and Chow came running up, having concealed themselves in the jungle during the struggle. As he drew near Chow stopped short and regarded the looming form with amazement. "G-Great jumpin’ jehoshaphat!" Chow stuttered, his jaw sagging open.

"Don’t worry," Bud assured him. "The guy’s friendly—I think!"

Before Tom could venture a comment, there was a further interruption. Several Mayan men came trotting into view, evidently drawn by the shouts and bellows. One look at the giant sent them melting away into the jungle like shadows.

"Ho, ho, ho!" the huge man guffawed. "Look at ’em run! I terrify ’em!"

"Just who are you?" he asked the giant.

"Maximilian Jones, that’s me!" he answered, thumping himself on the chest. "Former heavyweight wrestler from California, U. S. of A!"

"Why shor as shootin’!" exclaimed Chow. "Now I reconnize you! Used t’ watch you on TV."

"So you’re from California?" Bud grinned. "Say, that’s where I come from!"

"But I’m never going back," the giant added. "Not Max. No sirree!"

"Why not?" Tom asked.

"Because this jungle is the finest garden of health to be found on earth. You take it from me—I know. It made a new man out of me!"

"You mean you weren’t always this big?" Bud asked.

"Sure, I was big," the ex-wrestler replied. "But y’see, boys, I had some bad chromosomes, they said, and I didn’t stop growin’ like normal folk do. It’s not good for a fellow to grow that way—strains the whole system. So I had to give up my wrestlin’ career and had myself a long siege of illness. Sick in bed half the time, all sickly and pale and weak. Doctors couldn’t do a thing for me. Then I came down here."

"Sounds like one of those ‘Before and After’ health ads," Tom chuckled.

"Now don’t you laugh!—this is on the level," Max boomed. "I came here t’ die, but first I thought I’d consult a Mayan medicine man. He gave me some real potent stuff—herbs that he brewed himself. Had me back on my feet in no time! Of course the outdoor life helped too—that and the wonderful native food. The sun gives me energy, the rain gives me purity, and between them all, boys, they’ve turned me into a glowing picture of health!"

To emphasize his words, the ex-wrestler threw out his chest and flexed his mighty biceps. Tom barely managed to suppress a grin. He glanced quickly at his two companions. Bud responded with a wink, while Chow whispered out of the corner of his mouth:

"Punchy as a loco steer!"

Unfortunately, his words carried to Max. With a bellow of rage, the giant leaped at Chow!

TOM AND BUD hastily yanked Chow out of the way, a two-man task, and stepped in front of the enraged giant.

"Hold on!" Tom commanded. "That’s no way to treat a fellow American, is it?"

‘‘Well, that ain’t no way to talk about a fellow American, either," Max complained. "I heard what he said about me." The giant suddenly sounded like a sulky little boy. An injured look covered his broad pug face.

"I’m sure Chow didn’t mean any harm," Tom said soothingly, and the wide-eyed chef nodded emphatically and at great length. "Besides, we’d like to hear more about these health foods you’ve been eating down here."

Max brightened immediately and began to talk about the fruits, nuts, and roots that he lived on. From his enthusiasm, the three realized that the ex-wrestler was not only crackbrained on the subject of health, but a food faddist of the most rabid kind.

Chow, who had been keeping a respectful and wary distance from Max, now became interested. The cook was always eager to try out exotic new concoctions. In the past he had served such unusual dishes as armadillo soup and whaleburgers, and those who had sampled them had lived to tell about it. Perhaps some of the items Max the Magnificent mentioned might be worth trying, he thought.

Chow began questioning the giant and this seemed to please him immensely. Soon Max forgot his anger and became very friendly. "You fellows ought to come around and visit my cave some time," he boomed cheerfully.

"Do you really live in a cave?" Torn asked.

"Sure! Got it fixed up nice and homelike," Max boasted. "I even have a pet parrot and a lot of old relics."

Tom’s eyes flashed with interest at mention of the relics. If they were of ancient Mayan workmanship, it might be that some bore space symbols like the sacred stone of Quetzal’s tribe!

Meanwhile, Bud decided that he would risk a blunt question while the giant was in a good humor. "What were you doing skulking around our plane last night, Max?" he asked boldly.

Max looked surprised. "Now, how’d you know that?" he exclaimed. "I’ll bet someone snitched on me! That skinny little guy, eh? Well, it so happens I was chasing him!"

Tom and Bud looked at each other, mystified. "What skinny little guy?" Bud asked. "Someone from the village, you mean? One of the little Mayans?"

"Naw