Brothers John (Oliver Hudson) and Matt (Eric Lively) have inherited an island cabin from their recently deceased uncle. Along with Matt's girlfriend, Nicki (Michelle Rodriguez), and other mutual friends, the siblings travel to the cabin for a relaxing weekend getaway. But, not long after arriving, the group is besieged by ravenous dogs. They watch in horror as another vacationer, Luke (Nick Boraine), is eaten alive. Soon, they discover a training facility where the dogs have been bred to kill.