"Spirits of the Rainforest" is a feature documentary set in the remote Amazon rain forest of Manu National Park, in southeastern Peru. The film follows the intertwining stories of several researchers studying brilliantly-plumaged macaws and voracious giant otters as well as an American anthropologist (Dr. Glenn Shepard) living with a village of Machiguenga Indians, one of four ethnic groups that live in the park. The film follows the Machiguenga Indian Merino as he instructs his young son, Alejo, about the rain forest and also portrays the Machiguenga shaman, Mariano, who cures tribal members through the use of hallucinogenic drugs and in so doing visits with the forest spirits.