New experimental evidence suggests ancient Greek priestesses may have transformed the toxic ergot fungus into a psychedelic brew, known as kykeon, for the secret Eleusinian Mysteries. These rites, honoring Demeter and Persephone, aimed to alleviate the fear of death and involved rituals and the consumption of kykeon, which some scholars believe contained hallucinogenic substances. Researchers successfully detoxified ergot by boiling it in lye at pH 12.5 for two hours, a process that yielded non-toxic psychoactive compounds LSA and iso-LSA, related to LSD. The amounts produced per gram of ergot are sufficient to induce altered states of consciousness, potentially explaining the profound mystical experiences reported during the ceremonies.