Marcia, Mike, William and Katie are four old friends who have gone up to William's cottage for a weekend of card playing, drinks and walks in the woods. But all is not as it seems. Marcia is having an affair with William and Marcia's boyfriend Mike is beginning to suspect something. Things take an unexpected and horrifying turn when a malevolent force shows up and begins picking off the cottagers one by one. Forced to flee into the woods for their lives, Marcia's suspected infidelity seems all but forgotten. But it isn't.