Enthralled by the chronicle of a 16th-century Spanish monk, which said that the Incas 'flew like birds' over the jungle, and by the recurring theme of flying in Peruvian folklore, Tahir Shah set out to discover whether the Incas really did fly or glide above the jungles of Peru. Or was it flight of a different kind, inspired by powerful drugs? After gathering equipment in London the long quest begins, in the mountains of Peru, with a trek to Machu Picchu, the Incas' most sacred city. Then on to the mountain city of Cusco and a mysterious island on Lake Titicaca, before the trail of clues leads to the coast and through the desert, to the immense animal-like etchings which form the Nazca Lines and a remote burial ground for 30,000 mummified corpses. And finally to an epic river-journey up the Amazon to discover the secrets of the Shuar, a tribe of legendary savagery. Even for a traveller so used to surreal adventures, there are many strange encounters - some gruesome, some hilarious - among madmen and dreamers, sorcerers, con-men and jungle experts, before he can at last discover the truth about the Birdmen of Peru.