Some of the greatest mysteries are here on earth. But the darkest ones are within it. With the highest death rate of any sport known to man, spelunking is the most dangerous – and it is the setting of 'The Cavern'.

Kyzl Kum Desert, Central Asia – Eight explorers learn of a newly discovered cave system and set out on an expedition to document it. Once inside two of their guides are mysteriously killed, and when they try to escape, they find their way out has been inexplicably sealed shut. They’re trapped inside – and the only way to go, is deeper into the cave. They embark on a fight for their lives, hunted by an unknown presence, and threatened by divisions from within their own ranks.

Miles beneath the surface, surrounded by labyrinths of rock, sand, mud, and water, they must find a way to survive. They charge away at a breakneck pace to a frightening and thoroughly startling conclusion.

Some places should never be explored.