Synopsis: Some of the greatest mysteries exist on earth - but the darkest ones are within it.
In the Kyzyl Kum Desert, Central Asia, a team of explorers learn of a newly discovered cave system and set out on an expedition to explore it. However, as soon as they begin the descent, it quickly becomes clear that this was a secret that should have remained below the surface as members of the team find themselves caught in a desperate fight for their lives.