In the sweltering summer of 1518, the streets of Strasbourg became the stage for one of the strangest medical mysteries in history.  It started with one, and within days, dozens joined, their bodies moving to an unheard rhythm, unable to stop even as exhaustion and death loomed.  In this episode, we unravel the theories behind this eerie outbreak, from supernatural fears to psychological phenomena, and explore why, even centuries later, the true cause remains a mystery.