Five years after concealing a murder, guilt-stricken summer camp counselors return in midwinter to the scene of their crime, now a utopian commune.

After a body is found and a guest vanishes, both groups discover they're trapped at the camp with communication to the outside world cut off.

As the list of victims continues to grow, the number of possible suspects narrows and the two groups are forced to cooperate despite mutual suspicion.

The histories of several characters unfold in flashback, revealing surprising connections, while an innocent hiker is pulled into the unfolding drama.

Desperate to discover the identity of the killer preying on them, the remaining survivors reluctantly conduct a mock hearing to learn the truth.

Misinterpreted evidence points everyone in a false direction, while one camper finds evidence that makes him question the motive behind the slaughter.

The serial killer confesses to another camper, but the rest of the stranded survivors are still in the dark as final twists and truths are divulged.