TOM SWIFT AND HIS
G-FORCE INVERTER

by VICTOR APPLETON II

In the black depths of a crater on the hidden side of the moon, Tom Swift discovers a fantastic substance that promises to be the key to his newest and most far-reaching invention, a machine able to ingravitize matter and reverse the G-force!
  The discovery unleashes an unpre- cedented danger in space. But the greater threats are human ones. A former ally turns deadly as he wages an escalating campaign to compel the young inventor to find a thief who has stolen an invaluable object called The Picasso. The quest leads Tom and his pal Bud on a trip to Mexico City that ends in mystery and murder.
   Even as Tom and Swift Enterprises struggle to contain the threat, he undertakes a project to demonstrate the uses of his G-force inverter in en- gineering and construction. The Monoswift, a monorail train that floats in mid-air above the Grand Canyon, is Tom's main objective. But with gravity conquered, can he tame the three other fundamental forces of nature that confront him? Greed—fear—and love?