In a post-nuclear Eastern Europe, Hammel E Varka departs for a remote island to join a survey team cataloguing the abandoned Gollitok prison in the hopes that he will redeem his family's tarnished reputation. After the passage across the strait leaves a team member injured, Varka quickly realizes that this survey is far from routine and that what he thought he knew about the island was a cover for more horrifying truths. As his team presses deeper into the decaying facility, hidden agendas splinter the team, and they find themselves beset with dangers beyond their worst nightmares.