A year after her sister Melanie’s mysterious disappearance, Clover and her friends head to the remote valley where she disappeared in search of answers. While exploring an abandoned visitor center, they are stalked by a masked killer and gruesomely murdered one by one… only to wake up and 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 time more terrifying than the last. With hope fading, the group soon realizes they have a limited number of deaths left to commit, and the only way to escape is to survive until dawn.