Since 1995, hundreds of poor children in Muzaffarpur, India have mysteriously suffered seizures and feelings of brain fogginess, usually in the morning. Many would soon die. This happened every year between May and July: In 2014, for example, Muzaffarpur hospitals admitted 390 kids with the symptoms, resulting in 122 deaths.
What makes a mysterious disappearance even more intriguing? When baffling clues are left behind — or even more tantalizingly, when they surface again, months or years after the fact. Here are eight head-scratchingly compelling tales of people who vanished… and the weirdest theories they spawned.