On June 9, 1970 at the Meadowvale General Hospital, a doctor arrives to attend to three women in labor at the same time. During a solar eclipse, two baby boys and a baby girl are born during that time (off-camera with the total eclipse in view).Ten years later on the night of June 1, 1980, two teenagers named Duke and Ann are kissing in a local cemetery. Duke asks Ann if she wants to play "Ambulance" (a game involving his hand and her leg). Ann is afraid that someone might see them, so they move to kiss inside a hold in the ground. They hear some noise and Duke is suddenly smacked in his face with a shovel by an unseen person. Ann screams when another unseen person throws a jumping rope around her neck and she is choked to death while Duke is hit more with the shovel.Meanwhile, Joyce is eating a sandwich as her little brother Timmy comes through the kitchen window, saying that he was out feeding the dog and that the front door was locked. The next day, Joyce arrives at the Thomas Jefferson Elementary School where Sheriff Brody is talking to Miss Davis' class about murder. He shows the children a handle from a skipping rope and asks if anyone was in the cemetery last night when Ann and Duke were murdered. None of the children say anything and he leaves, saying goodbye to his daughter Debbie. After class, Debbie and her two friends, Curtis and Stephen, ask Miss Davis if everyone can be excused for their birthday party next week. The request is denied.Later, the three children dine one some cookies, and Debbie charges the boys to watch through a hole in the wall. They see Beverly, Debbie's older sister, dance and undress. Another time later, Debbie is skipping rope and calls her father outside. Sheriff Brody narrowly misses stepping on a skateboard (carefully placed there by one of the boys), and Debbie drops her skipping rope (missing a handle). Stephen then suddenly attacks and beats the sheriff with his baseball bat when he bends over. While Stephen and Curtis move the body, Debbie spots Timmy watching and she decides to quickly call for her mother.After the sheriff's funeral, some kids are playing a game in the local junkyard. Curtis tricks Timmy into hiding in a old refrigerator and locks him inside. Timmy manages to escape and returns home where he tells Debbie where he was. He then admits that the other night he was over at Debbie's house (she was not there) to see the Beverly peep-show. Joyce says that she does not want Timmy to play with Curtis anymore.Meanwhile, Debbie puts a picture of Miss Davis in her scrapbook, which also contains an article of her father's murder. That night, Debbie turns off the house security system, and she and Curtis switch his replica gun with the sheriff's real gun. Later at school, Curtis stand behind Miss Davis with the gun and shoots and kills the teacher. Debbie, who is outside, says hello to an approaching Timmy and Joyce. Joyce goes inside the school, where Stephen is hiding in a closet. Curtis runs outside and is decked by Tommy. Joyce then finds Miss Davis' body in a closet.Joyce returns home to find a note from Timmy, telling her he is in the junkyard. She goes looking for him there, and she finds Timmy's tiny flashlight in the refrigerator. Stephen (with a cloth covering his face) hot-wires a car and tries to run Joyce over, with Curtis assisting in operating the pedals. The two murderous boys finally tie down the gearshift, and the car flies by Joyce and goes over a small cliff. A police officer arrives and Joyce tells him what has happened.That night, Joyce is discussing astronomy with Timmy. She says that the solar eclipse that occurred during the births of Debbie, Curtis and Stephen wound have blocked Saturn, the planet which controls the way a person treats other people. Curtis is outside with the gun, but he decides to go across the street where a teenage couple is making out inside a van. The man checks a noise and is shot the head by Curtis. Curtis then enters the van and shoots the woman.A few days later, at the murderous trio's 10th birthday party, Debbie tells Curtis that Joyce might know too much, but he assures her that no one will believe Joyce about the three of them being sociopath killers if she is thought to be crazy. Curtis begins putting more icing on the cakes; Joyce sees him there. When she goes for another cake, she sees Curtis is hiding a bottle of ant poison behind his back. Joyce runs outside and tells everyone that Curtis has poisoned the cake. Curtis' grandfather is upset that Joyce with accuse the innocent little boy of such a transgression, and both he and Curtis try some icing on the cake to show everyone that nothing is wrong. Joyce realizes (too late) that Curtis pretended to poison the take to make herself look like a crazy fool.At home later that evening after the party ends, Joyce tells Timmy that Curtis did not seem to know he was doing anything wrong. She suspects that Curtis, Debbie and Stephen have have been born without guilt for their actions. When Joyce investigates a noise, but it is only her boyfriend Paul who comes out to scare her. The couple hugs.Beverly inadvertently discovers Debbie's scrapbook, titled "Clippings of murder". Beverly shows it to her mother and they both confront Debbie who lies (like the natural born sociopath that she is) by claiming that Curtis left it. Beverly burns the book. Debbie then phones Curtis and Stephen and tells them to come on over. She then readies an arrow with her bow, points it at a hole in the wall and raps the arrow against the wall until Beverly looks through and is gorily shot through her eyeball with the arrow. The boys arrive at the house a little later where after seeing Beverly's dead body, Curtis calmly asks "why didn't you wait for us?" The three murderous children move the body out by the trash.Following Beverly's funeral, Debbie's distraught mother goes to the hospital. When Debbie is playing with Curtis and Stephen at her house, Timmy throws some rocks at the windows (but the "special glass" does not break). The evil trio chase Timmy down, put a garden hose around his neck and cover his mouth. Joyce sees them and Debbie feigns pleading with the two boys to stop hurting Timmy. Curtis then mocks Joyce for the party incident and the warped children leave after releasing Timmy.Joyce is now added to Debbie's scrapbook. Debbie then calls Joyce to tell her that her mother will be coming home from the hospital, and she then asks Joyce and Timmy to babysit. That night, as Timmy sleeps and Joyce listens to her earphones, Debbie lets her twisted pals inside. Curtis rewires the security system while Stephen cuts the phone line. Timmy awakes just in time to see Curtis point his gun at him. Timmy and Joyce run as they dodge Curtis' bullets as well as Stephen's arrows and Debbie's skipping rope. The two siblings cannot open the doors or break the windows, so then run into Debbie's bedroom, where Debbie and Stephen fire arrows through the closed door. Stephen manages to get inside the bedroom, but Timmy and Joyce manage to lock him inside a trunk. Outside the room, Joyce manages to grab the sheriff's gun, but Curtis appears and lets her know that is is only a replica. He pulls the trigger, but the gun only clicks (Curtis is finally out of bullets) and Timmy tackles him down and ties him up with electric cords. Joyce then whacks the security system on and Timmy runs outside for help. Debbie sees her mother arriving by car and tells her that Curtis and Stephen did some very bad things for which she will be blamed. Still believing her innocent-faced daughter, Debbie's mother bundles her in her car and the two drive away.The next day, Curtis and Stephen are handcuffed and taken away by the police. Curtis smiles at Joyce in a very evil manner as he is being hauled into a police car. Joyce and Timmy give their statements to the police and learn that Debbie and her mother are missing and that the police will now be looking for them.In the final scene, Debbie is seen outside a model, messing with a car jack. Her mother comes outside after checking out of their room and makes sure that Debbie knows her new name which is "Beth Simpson". As Debbie and her mother drive away, a man is seen lying dead; crushed underneath a nearby parked truck.