Valerie (Amanda Seyfried) is a beautiful young girl, in love with an outlaw, Peter (Shiloh Fernandez), but her parents have arranged her marriage to the wealthy Henry (Max Irons). Willing to sacrifice everything for their love, Valerie and Peter are planning to run away together, but their escape is turned upside down by tragedy. Sister girl is brutally murdered by a werewolf, a creature that inhabits the forests around their village and villagers who for years kept a fragile pact, sacrificing an animal and every month. But one bloody night moon, the werewolf truce and dare to take a human life.
Hungry for revenge, the villagers seek help Father Solomon (Gary Oldman). But the arrival of unexpected consequences, for it warns that the wolf takes human form by day and could be any of them. The death toll of the month increases with every sunrise and Valerie discovers he has a special bond with the beast – one that inexorably draws them toward each other, and it becomes a suspect, but also … bait.