From the early Middle Ages to the 19th century, a mysterious pandemic—more deadly than the Black Death—ravaged Europe. Known as “Saint Anthony’s fire,” it was caused by the same fungus behind LSD, triggering terrifying and ecstatic hallucinations reflected in art and legend.

For the first time, scientists and historians join forces to unravel this story, beginning with a striking clue: a severed foot at the center of a triptych by Hieronymus Bosch.