A year after her sister Melanie mysteriously disappears, Clover and her friends travel to the remote valley where she disappeared in search of answers. While exploring an abandoned visitor center, they discover that a masked killer is stalking them, killing them one by one in horrific ways… only to wake up to find themselves back at the beginning of the same evening. Trapped in the valley, they are forced to relive the nightmare over and over again – only each time the killer’s threat is different, each more terrifying than the last. Hope fades, and the group soon realizes that they have a limited number of deaths left, and the only way to escape is to survive until dawn.