In the summer of 1998, people are killed and begin to disappear in the town of New Hampton, NY. Nobody knows why. Four teenage boys on a fishing expedition accidentally end up trespassing on private property. They discover an underground cave with tunnels and end up finding clues to the mystery. For some reason, the attacks only occur at night. The attacker knows the town well and always eludes capture. As more evidence surfaces, the four teenagers turn to the local Catholic priest for help. The bishop of the diocese authorizes an ecclesiastical investigation to take place in New Hampton. Seeking the help of medical experts, the police, and the four teenagers, a group of committed priests uncover the nature and magnitude of the evil. As more residents become victims, an old town secret is revealed. The town's history provides the tools necessary to successfully exterminate the evil in New Hampton.