Mikey is a young boy around 10-years-old, whom is first seen lighting papers on fire with his five-year-old stepsister Beth. When Mikey's foster mother finds him burning papers in the garage, she yells at him and takes Beth away with her. Mikey says that he hates her and that she is not his real mother. He takes Beth's doll away, run to the backyard swimming pool and drops the doll in from the diving board. Beth reaches for the doll, and Mikey jumps on the board causing Beth to fall in and drown. Mikey walks into the bathroom where his mother is taking a bath, saying that she does not love him anymore. He picks up a blow-dryer, turns it on and throws it into the bathtub, electrocuting his adopted mother. Mikey then puts ball bearings on the floor near the back door. When his adopted father comes home and runs to the pool after Mikey tells him that Beth fell in, he slips on the ball bearings and crashes through the screen glass door. Mikey then beats his adopted father to death with a baseball bat as a video camera records. Detective Reynolds arrives on the scene with the police after Mikey calls them and describes a man leaving the house. Katherine, a social worker, takes Mikey away.Mikey lies to a doctor about a man being in the house and claiming "I hate him!". The sister of Mikey's adopted mother refuses to take care of him, so a childness couple, named Rachel and Neil Trenton, adopt Mikey. The couple brings Mikey home where Mikey asks to take care of the baby fish in the couple's aquarium. Mikey then meets his neighbor Ben, a boy his age and the two of them become fast friends. Mikey also meets his teacher and Rachel's friend, Shawn Gilder. Neil takes Mikey to an archery range, and Mikey is shown to be a natural with a bow and arrow.In his third grad class at school, Mikey learns about "marble time". A student adds a marble to a collection, and when full, the door opens for a prize. At home, Rachel and Neil look at a drawing Mikey made of a "swimming girl" and believe it is symbolic of something good. After school, Ben brings Mikey over to his house where Mikey eyes a photograph of Ben's older sister, Jessie, who is away at college.Another day later after class, Mikey adds marbles to the collection. Shawn sees this and tells Mikey that he can only add one marble at a time, but Mikey refuses and wants the prize from the marble box. Shawn tells Mikey to tell his parents what he has done. Later, Shawn learns that Mikey did not tell Rachel of the marble incident when she says nothing about it. Another day later the class draws pictures, and Mikey draws a turkey "fixing" a pilgrim (chopping his head off). Shawn shows the picture to the principal Mr. Jenkins, believing that Mikey has "unattached syndrome" (psychotic behavior), but Jenkins thinks that her assessment if premature. Shawn goes to her friend, Eva, in the records department to look up Mikey's past but she is told that his records are sealed. Later, Jenkins talks with Mikey about the drawing, and about his family. Mikey tells Jenkins that his real parents died when he was only five and that they were "bad". Mikey admires a skeleton of a child in the office.When Jessie comes home, the two boys pretend that Mikey is unconcious. Jessie give him to mouth-to-mouth to revive him where Mike "wakes up" and tells her that this is all a joke that he and Ben cooked up. Mikey tells Jessie that he had a ball under his arm so that Jessie would not feel his pulse. That night, Mikey crawls into Jessie bedroom through the window and watches her sleep.In class, Mikey wins a spelling contest and refers to a triumph in Oklahoma City. Shawn calls a teacher at Mikey's old school in Oklahoma City and asks about Mikey, and the teacher talks about the "tragedy" of Mikey's murdered foster family. After school, Mikey goes to Ben's house (knowing that he is not there) and asks Jessie if she would like to come for a boat ride with her since he was going to ask Ben, and she agrees.That night, after Mikey watches the video of his stepfather crashing through the glass door from the opening scene, he is tucked into bed and asks Neil how someone knows if he loves a girl. Late that night, Mikey sneaks out again and goes with the video camera next door to Jessie's room to videotape her while she sleeps and he is upset when he sees her making out with David, her college boyfriend. Mikey throws a rock through Jessie's window. David runs outside as Mikey hides in the bushes and snaps the neck of Jessie's pet cat Rosie (revealing that Mikey has near-super strength). Jessie is now tired and asks David to leave. He gets in his truck to drive away when he hears something and after getting out sees that he has "run over" Jessie's cat. He tells Jessie who is upset.Behind a pop-up book in class, an angry and frustrated Mikey incessantly stabs his arm with a thumbtack. Shawn asks to see the book that he is reading and she sees his wounded arm. Both Shawn and Jenkins tell Rachel and Neil that Mikey should see a therapist, but the couple becomes agitated and tells them that they will deal with Mikey by themselves and do not need help or advice on how to raise Mikey from anyone.At home, Mikey sees the baby fish gone from the aquarium and Rachel tells Mikey that some man bought the fish. Mikey throws a fit and tells Rachel that she does not love him anymore because she sold his fish. Later, as Rachel is in the bathtub taking a bath, Mikey walks in and picks up a curling iron that is plugged in. He talks about throwing it into the tub with her, but for some reason, Mikey changes his mind, unplugs it and walks out... and saying to himself that the time is still not right.Mikey spies on Jessie and watches David apologize to her about killing her cat, and Mikey is perturbed by the apparent success of the apology. That night, as David and Jessie play in the backyard pool, Mikey dials Jessie's number and puts the phone by the running TV set. As Jessie goes into the house and answers the phone, Mikey approaches the Jacuzzi and kicks the radio beside it into the water and quickly retreats. Jessie returns to find a dead and floating David.Another day or two later, Shawn talks on the phone with Detective Reynolds about the Mikey case and asks to see the police reports on Mikey's murdered stepparents since the Oklahoma City police have closed the case after declaring it unsolvable. Reynolds says he will fax over a copy to the school in the morning. Jenkins gets a call and is told by Neil that Mikey and Ben will not be at school today due to the "accident" at Ben's house.Mikey talks to a melancholy Jessie and tells her now that David is dead, she can just love him. Later, Jessie goes to see Rachel and says that she believes that Mikey loves her and that he is dangerous and may have killed David. Rachel refuses to believe her and yells at Jessie to leave. Mikey listens from the stairs. After Jessie leaves, Mikey takes the phone off the hook and decides the time has come to get rid of his foster parents and everyone who knows him.At the school, Shawn reads the fax from Reynolds and learns of the death of Mikey's foster parents (apparently the second or third set of parents, including Mikey's real parents, who died from mysterious "accidents" caused by electrocution). She tries to call Rachel, but the phone is busy. As she is leaving the school grounds, Jenkins goes with her and agrees that Mikey is dangerous.At the house, Rachel hears screaming and sees Mikey watching the video of him killing his previous foster parents and claims that he is watching "Mikey's Funniest Home Videos". She tells him to go to his room, but Mikey instead whacks her on the hand with a hammer. He swings it at her again, in which she ducks and it hits the aquarium. Rachel runs downstairs and wraps her hand in a bandage, but Mikey appears and breaks her arm with the hammer and she pushes him down and runs into her room, locking the door. Mikey breaks down the glass door and gets into the room. He attacks her with a glass shard, and actually begins to overpower Rachel with his near superhuman strength. During the struggle they both tumble over a balcony railing and tumble down the stairs. Shawn and Jenkins arrive minutes later to find both Mikey and Rachel at the foot of the stairs (the glass shard is in Rachel's neck and she is dead while Mikey is apparently unconscious).Jenkins takes Shawn's gun while she waits outside. Jenkins puts the gun on the kitchen counter as he picks up the phone to call the police, but only gets a busy signal for the phone is still off the hook in another room. Mikey regains consciousness, goes to the kitchen, picks up the gun and a minute later puts it back. As Jenkins sees the off-the-hook phone and hangs up so he can pick it up again to call the police, Mikey appears with a bow and arrow. Jenkins aims his gun at Mikey and pulls the trigger but nothing happens and Mikey reveals to have taken the bullets. He then shoots Jenkins through the heart with an arrow. Shawn goes inside and sees Jenkins dead. Mikey then slingshots a marble made from steel at her face, killing her as well.A little later, when Neil calls, Mikey tells him that Rachel is not feeling well and to come home soon. Mikey then drags the dead bodies of Rachel, Jenkins, and Shawn to a table and turns on the gas oven. He bushes his hair and goes next door to see Jessie and asks if he can come in. She says 'no' and goes up to her bedroom where Mikey appears after crawling in through the open window and asks Jessie if she likes him. She pushes him out the door, but goes downstairs when she hears the TV set on and the video of Mikey killing his foster parents is playing. Mikey appears with his bow and arrow again and Jessie runs back to her room as he shoots, but misses.Neil arrives home, and Mikey quickly retreats and goes home. Jessie sees him and tries to warn him, but Neil think that she's only waving. Inside, Neil seed the dead people and the child skeleton from Jenkins's office at the dinner table. As he screams, Mikey tosses in a flaming bottle and the entire house explodes, killing Neil. When the police and fire department arrive, they question Jessie and Ben about what happened and one fireman tells her that the remains of a 10-year-old were discovered. Jessie and Ben are beside themselves wondering if Mikey really is dead.At the same time, Mikey makes it to a nearby expressway and a police car stops for him and, thinking that someone abandoned him, takes him into protective custody. Mikey feigns amnesia and tells them that his name is "Josh". Once again for the countless time, the police and social services do not make any background check on Mikey and in the final shot, a social services man tells a childless couple to meet their new adopted son, Josh. Mikey walks into the room and asks "are you my new family?"(Another one of those annoying and cliché here-we-go-again endings as Mikely smiles devilishly at the camera as he is adopted into foster family number three to begin his murderous cycle all over again).
Output: Question: How old is Jessie?, Answer: 15 years