A werewolf besieges a family reunion in a secluded cottage during a raging thunderstorm as the terrified people inside fight for survival. Sarah's family is notoriously dysfunctional. But with the full moon shining bright in the night sky, she reluctantly heads into the country for a rare visit with her siblings and a few close friends. Meanwhile, in the pouring rain, a walking nightmare approaches the cabin, and launches a ferocious attack. One by one, it devours the inhabitants until only a few are left standing. As the desperate survivors start to turn on one another, the beast outside proves no match for the savagery of a scored relative.