The village of Kalachi, Kazakhstan, is a small town of 600 inhabitants, where residents, including children and the elderly, often fall asleep, only to wake up days later feeling as if they've never rested.
These episodes have been happening for a couple of years now, everywhere and without warning, so much so that there isn't a single resident who doesn't have a relative or friend who hasn't experienced them .
And no one can explain why, not even doctors, despite having performed all sorts of tests. Many have begun to view the abandoned former Soviet mine nearby with suspicion.
In April 2013, the first wave of cases of the mysterious "sleeping epidemic," as it's known locally, was recorded. Since then, the syndrome has struck one in ten residents, often more than once, sometimes with slumbers lasting a whole week. On one occasion, it affected more than 60 people at once.