"Soma" explores the intriguing hypothesis that the mysterious ritual drink called 'soma,' referenced in ancient Indian Vedic texts, was derived from a psychoactive mushroom. The book delves into linguistic, cultural, and ethnobotanical studies to support this theory, suggesting that the Amanita muscaria mushroom is the most likely candidate for the original soma. Through a detailed examination of the Rigveda, the author argues that soma played a central role in early Indo-Iranian religions, influencing spiritual practices and experiences. The work combines historical analysis with the study of religious rituals to shed light on how psychoactive substances have shaped human culture and spirituality.

The book is a fictionalized account of the life of Fray Servando Teresa de Mier, a real-life Dominican friar from the 18th century. It follows his numerous escapes from colonial authorities across Latin America and Spain after he delivered a controversial sermon in Mexico City. The narrative, infused with magical realism, portrays Fray Servando's adventures and misfortunes as he becomes a symbol of freedom and resistance against oppressive regimes. His journey is marked by a series of bizarre and fantastical encounters, reflecting the author's critique of totalitarianism and exploration of the themes of liberty, identity, and the absurdity of political persecution.