Botanist Piers Gibbon goes on a quest to sample the hallucinogenic ayahuasca, which Amazonian shamans drink to enter the spirit world and talk to the plants. After injecting an uncontrollable dose of frog poison Piers finds a shaman who is prepared to reveal his supernatural secrets. But he must prove his commitment, by spending several nights on his own drinking the ayahuasca brew. How far is he prepared to go in pursuit of knowledge and experience, and will he ever find his way back again?