One year after her sister Melanie mysteriously disappears, Clover and her friends travel to the remote valley where she vanished in search of answers. While exploring an abandoned visitor center, they are stalked by a masked killer and brutally murdered one by one… but awaken to find themselves again in the early hours of the morning. Trapped in the valley, they are forced to relive the nightmare over and over againβeach time the deadly threat changes, each time more terrifying than the last. As hope dwindles, the group quickly realizes that they have a limited number of kills left, and that the only way to escape is to survive until dawn.