Man conquers the skies at last! Unparalleled inventor Frank Reade Junior has mastered heavier-than-air travel with his incredible new Air Canoe. And what better feat to attempt with his miraculous new invention than the exploration of the legendary Valley of Diamonds of the Amazon? Said to be guarded by the ferocious mapinguary, mythical Bigfoot of Brazil, no outsider has ever been able to penetrate the jungle and witness its incomparable diamond riches. Can Frank Reade Junior's miracle of science succeed where all others have failed?