Secluded Necklan's Lake is where the Senior Class goes to party after the prom. Tradition calls for skinny dipping in the frigid waters, after drinking enough to build up the courage. There's beer, a bonfire, loud music, brief nudity, and sometimes —- terror and death. The forensic science intern has been assigned the cold case by the local Sheriff. As she seeks a solution, the forces that caused the massacre are converging to repeat it.