The Eleusinian Mysteries were a set of religious rituals and initiations that took place in ancient Greece, particularly in the city of Eleusis, in honor of the goddesses Demeter and Persephone. The details of these mysteries were kept secret, and participants were sworn to secrecy, so our knowledge of the rituals is limited. There are several books available that discuss the Eleusinian Mysteries, their significance, and their role in ancient Greek religion and culture. Some notable works on this subject include: "The Road to Eleusis: Unveiling the Secret of the Mysteries" by R. Gordon Wasson, Albert Hofmann, and Carl A. P. Ruck: This book explores the use of psychoactive substances in the Eleusinian Mysteries and presents a theory regarding their potential role in the mystical experiences of the participants. "The Eleusinian Mysteries & Rites" by George Mylonas: This book provides a comprehensive examination of the Eleusinian Mysteries, including their historical context, rituals, beliefs, and their influence on Greek society. "Eleusis: Archetypal Image of Mother and Daughter" by Carl Kerényi: This book focuses on the mythological aspects of the Eleusinian Mysteries and explores their connection to the mother-daughter relationship between Demeter and Persephone.