July 1518. Strasburg. Mrs. Troffea began to dance and didn’t stop dancing. After one week, 34 more people danced along with her. After a month, the total number of the dancers reached several hundred. They danced without stopping, and 400 people died of exhaustion, heart attacks, or strokes.

This phenomenon doesn’t have any satisfactory scientific explanation. None of the theories explain the unbelievable stamina needed to dance for several days without stopping.