A year after her sister Melanie mysteriously disappears, Clover and her friends head to the remote valley where she disappeared in search of answers. While exploring an abandoned visitor center, they find themselves being stalked by a masked killer and horribly murdered one by one… 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 threat is different, each more terrifying than the last. As hope dwindles, the group soon realizes they have a finite number of dead and the only way to escape is to survive until dawn.