An American doctor goes to Peru to learn about ancient native Indian practices. He starts and ends in the rainforest with the Shipibo shamans who introduce him to the hallucinatory ayahuasca practices. He describes the ceremony and his experiences during the trance he undergoes. Most of the book is about his exploration of the indigenous Q'ero people who continue to put into practice pre-Incan spiritual beliefs. As he experiences and even conducts shaman rites, he explains the belief system of the Q'ero, with its emphasis on beauty, right action, respect for all life, and reciprocity, similar values to the Hopis and Navajos. Williams lives among them, high in the Andes, and learns their ways, interpreting them for readers. A very interesting introduction to these ancient, and wise, ways that I knew little about before reading this.