Victor, Dan and Tom skip school to wander around an abandoned amusement park. They stumble upon a horrific vision: a woman in chains is dragged through the field by a man wearing a clown mask. The masked man catches a glimpse of the boys, who scramble to run away. But, before they can escape, they see something which has been hidden for years, something they were not meant to see. Terrified of having been seen by the masked man, the boys try to alert the police. Unfortunately, their past record of unruly behaviour discredits them and the police do not follow up on their tip-off. That night someone breaks into their homes, seeking to eliminate them one after another. They are going to meet Klarence...