This podcast episode explores the ancient mystery religions of the world and their possible psychedelic roots, specifically focusing on the Greek Mysteries of Eleusis. The guest, Brian Muraresku, discusses his book "The Immortality Key: The Secret History of the Religion with No Name," and presents evidence for the use of psychedelics in ancient rites. The conversation covers topics such as the historical significance of the Mysteries, the destruction of the Mysteries by early Christians, and the influence of these ancient rituals on the development of early Christianity. The episode also touches on the pagan continuity hypothesis, the cult of Dionysus, the Dead Sea scrolls, and the Gnostic Gospels. Overall, the episode reveals the profound impact these mystery religions had on the spiritual and intellectual life of ancient civilizations and their potential connection to modern religious practices.