A year after her sister Melanie’s mysterious disappearance, Clover and her friends travel to the remote valley where she disappeared in search of answers. While exploring an abandoned visitor center, they are chased by a masked killer and gruesomely killed one by one, only to wake up and find themselves back at the beginning of the same night. Trapped in the valley, they are forced to relive the nightmare over and over again – only each time the threat of murder is different, each more terrifying than the last. As hope fades, the group soon realizes they have a limited number of deaths left and the only way to escape is to survive until dawn.