0:00 In July 1518, a woman named Frau Troffea walked into a narrow street in Strasbourg and started to dance.0:07 Now, last week we talked about London's Great Stink of 1858, and how a physical crisis forced Parliament's hand, which at least makes a kind of grim, logical sense.0:18 This is something else entirely.0:20 Frau Troffea didn’t stop dancing for almost a week.0:24 And by the end of that week, she wasn't alone.0:27 Within days, thirty-four other people had joined her.0:30 Within a month, there were four hundred.0:33 Four hundred people, dancing silently, without music, in the summer heat.0:38 They weren't celebrating.0:40 Their faces were contorted in agony.0:42 They were just… compelled to move.0:45 Historical records say they danced until they collapsed from exhaustion, from strokes, from heart attacks.0:52 Some danced until they literally died.0:55 So what do you do when your city breaks out in a deadly, spontaneous dance party?1:00 The city leaders were completely baffled.1:03 They consulted physicians, who ruled out any astrological or supernatural causes.1:09 Their diagnosis?1:10 "Hot blood." A natural disease caused by an overheated temperament.1:14 And their prescription was, I promise you, one of the worst medical decisions in history.1:21 They decided the cure was MORE dancing.1:23 They figured the dancers just needed to get it all out of their system.1:28 So they cleared out two huge guildhalls for them, they even built a wooden stage in the middle of the market.1:36 They hired professional musicians to play pipes and drums to keep the beat going, to encourage the fever to burn itself out.1:44 Of course, it did the exact opposite.1:47 Seeing an official stage, hearing music — it just drew more people in.1:52 The whole thing became a state-sanctioned death rave.1:55 So what in the world was going on?1:58 For centuries, the go-to theory was ergotism.2:01 It’s a type of fungus that grows on damp rye, which was a staple grain.2:06 Ergot poisoning can cause muscle spasms, convulsions, and vivid hallucinations.2:11 It's the fungus from which LSD was first synthesized, so you can see the connection.2:17 It’s the "poisoned bread" theory.2:19 And it sounds plausible, right?2:21 A whole town eats bad bread and starts tripping uncontrollably.2:25 But here's where that analogy breaks down.2:28 Ergot poisoning also causes gangrene — it constricts blood vessels so much your limbs can turn black and fall off.2:36 And it doesn't typically cause coordinated, sustained movements for days on end.2:42 It causes twitching and seizing.2:44 The symptoms don't quite match the dance.2:47 The more likely answer is something far more unsettling.2:51 Mass psychogenic illness.2:52 Or what used to be called mass hysteria.2:55 You have to understand what life was like in Strasbourg in 1518.3:00 They'd just been through multiple famines.3:02 There was poverty, disease — syphilis was rampant.3:06 And on top of all that, there was an intense, almost suffocating religious superstition.3:12 People lived in a state of constant, high-grade stress.3:16 Their lives were BRUTAL.3:17 So the theory goes that this wasn't a poison in their bodies, but a poison in the culture.3:24 A collective psychological break.3:26 Frau Troffea started it, maybe in a trance-like state brought on by her own private grief or stress, and it became a social contagion.3:35 In a world where people truly believed in demonic possession and divine punishment, seeing your neighbor dance uncontrollably wasn't just weird — it was a possibility for YOU.3:47 The stress found a physical outlet, and that outlet itself became a new source of terror that spread through sight, like a virus of the mind.3:57 We've seen this shape before, in different forms.4:00 The Tanganyika laughter epidemic of 1962, where hundreds of schoolgirls couldn't stop laughing.4:07 It's the same pattern: a high-stress population, a trigger, and a belief system that allows the behavior to SPREAD.4:15 It's easy to look back five hundred years and call it superstition.4:19 But the Dancing Plague is a profound reminder that the line between individual minds and a collective consciousness is… porous.4:28 That under the right pressure, a group of people can fall into a shared psychosis, a waking nightmare they can't escape.4:36 The cure wasn't more dancing, and it wasn't a poison antidote.4:41 The cure was letting the fever break.4:43 But first, it had to burn through an entire city.4:46 It leaves you with a really chilling question: what happens when the sickness isn't in your body, but in your belief?
