Fact1: Something sounding like large swarm of birds is heard approaching, Fact2: Richard Vineyard and young son leave suburban home for camping trip, Fact3: fellow camper tells story of Jersey Devil, Fact4: Richard is awakened in middle of forest having run from tent while asleep, Fact5: Cynthia is second wife after loss of Sadie 's mother decade prior
Output: Two young campers walk together through the woods, commenting that there are no animals or birds around. They discover a pile of mutilated deer carcasses left on the trail. They are chased by a mutilated deer that drops dead in front of them. Something sounding like a large swarm of birds is heard approaching. Richard Vineyard, his wife Cynthia, his daughter Sadie, and his young son Danny leave their suburban home for a camping trip. They want to leave civilization behind and bond as a family in the Barrens, a forest in southern New Jersey. On the way to the campsite, they see a mutilated deer crossing the road. They stay in a crowded commercial campsite full of obnoxious campers who are not inclined to abandon civilization: cell phones and loud music abound. While setting up his tent, Richard has a flashback to a traumatic event from his childhood that occurred in the Barrens. Later that evening, when a fellow camper tells a story of the Jersey Devil, the campers pull a prank that scares the Vineyard family. Richard overreacts, much to the embarrassment of the rest of the family. That night, Richard has a nightmare in which he is being chased through a field by something unseen. He is awakened by Cynthia in the middle of the forest, having actually run from their tent while asleep. He accuses his wife of infidelity; she doesnt understand his suspicion and tries to reassure him. Richard apologizes. Cynthia returns to the tent and Richard goes for a walk. He sees a deer carcass fall from a tree. Several facts are revealed in conversation the next day. Richard is taking pain medication for a wound received before they left home. Cynthia is his second wife after the loss of Sadies mother a decade prior. One of the campers involved in the prank the previous night is missing. Richard, who appears weakened by illness, leads his family deeper into the forest away from the trails to a new camp site. While resting, Danny finds the disemboweled corpse of the missing camper but says nothing. Richard begins hallucinating and becomes irritable. They find a campsite containing a decomposed dog, a shredded tent, and furs hanging to dry, but no people. They decide to set up camp there. Richard disposes of the dog, and discovers that another camper, Ryan, has been following them and is communicating secretly with Sadie by cell phone. Richard returns to the campsite and tries to take Sadies cell phone away. Cynthia announces that they are going home the next day. That night, Sadie searches for Ryan. She is frightened by something in the woods. It is revealed in conversation that Richard killed the familys rabid dog before they left home because it bit him. Richard’s mental state deteriorates. Richard sleepwalks again, awakening surrounded by mist. The Jersey Devil appears behind him. Cynthia gathers the family and they leave immediately, but Danny and Richard get ahead and disappear. Cynthia calls the police, and she and Sadie discover Ryans disemboweled corpse; Richard’s knife is next to the body. They find Danny face down in the river, but are able to resuscitate him. Richard returns but has a seizure. He attacks Cynthia and breaks her leg. Sadie knocks him unconscious and ties him up. Sadie and Danny leave to find help, leaving the severely injured Cynthia with her hysterical husband. Cynthia passes out from the pain. Richard sees the Jersey Devil again. Richard breaks free of his bonds. Cynthia knocks her husband out with a rock, but when she checks on him a few minutes later Richard has vanished. Cynthia screams as she is suddenly attacked by something unseen. Sadie and Danny encounter a cougar but are rescued by a hunter. The police find the bodies of the missing campers. The hunter, Sadie, and Danny find Richard and Cynthia. Richard attacks the hunter and acquires his rifle. Richard seemingly turns on his family with the rifle. He sees the Jersey Devil behind them. For the first time, the others see it as well. Richard attempts to shoot it, but he is instead shot by the sheriff who thinks he is aiming at Sadie. The Jersey Devil attacks and kills the sheriff and then turns on the Vineyards. A forest ranger witnesses the monster attack and flees. Sometime later Sadie is being interviewed by the authorities before being reunited with her brother, her story of what she and her brother saw being dismissed as psychological trauma.