Plot summary

Sarah Fittler and her nine-year-old son take a taxi to return home from the cinema, but are abducted by the driver, Bob, and brought to his house. As a result of abuse his father inflicted on him and his brother, Bob is a serial killer who rapes and murders young women he captures. He kills Sarah and forces her son, whom he renames "Rabbit", to become his personal prisoner. When Rabbit tries to escape, Bob chains him to the wall.Years later, the now teenage Rabbit remains chained in Bob's home doing housework and burying the bodies of Bob's victims. While still holding the young man captive, Bob tries to become more of a father figure and has Rabbit educate himself about human anatomy. To make Rabbit believe nobody else cares for him, Bob reveals that Rabbit's father Brad has remarried. He also releases Rabbit from his chains. However, in bringing Rabbit closer, Bob intends to have Rabbit follow him in becoming a serial killer.In an effort to complete Rabbit's transformation into a serial killer, Bob asks him to pick a victim from a yearbook. Rabbit initially refuses, but when Bob forces him to make a selection, he chooses a girl named Angie and Bob abducts her. Leaving Rabbit and Angie in a room, Bob warns Rabbit that he will kill the girl if Rabbit does not. Rabbit hesitates and starts to bond with Angie, but stabs her in the stomach when Bob barges in. He then drags her body into the room containing the corpses of past victims. Satisfied with Rabbit's development, Bob agrees to his request to hunt for another girl.Bob brings Rabbit in the city with his cab and suggests several potential victims, but Rabbit declines them all. As they continue to drive, Bob discovers that Rabbit has written the word "help" on the side of the cab. Bob then realizes that Rabbit did not kill Angie, but stabbed her in a non-lethal location using his knowledge of anatomy and hid her where the other bodies are buried. He knocks Rabbit unconscious and enters the room where Angie is hiding to kill her. Angie manages to cut Bob's Achilles tendon while Rabbit awakens and comes to save her. Following a struggle, Rabbit kills Bob and buries him next to his victims.With Bob dead, Rabbit tracks down Brad, now living with his new wife Marie and Rabbit's half-brother Colin. His father feigns delight about his survival until Rabbit, whose real name is revealed to be Tim, confronts him with the knowledge that Brad had arranged the abduction of him and his mother. Through a letter he found, Tim discovered that Bob is Brad's brother and Brad, who had urged Sarah to take a taxi the day of the kidnapping, wanted to get rid of his first wife and son. Brad responds to this revelation by physically assaulting Tim and then Marie when she intervenes, prompting Tim to beat him to death. After Tim leaves at Marie's urging, Marie calls the police and tells them that a burglar killed her husband.Tim returns to Bob's house and shuts the garage door. As the closing credits roll, the sounds of him entering the house, opening the fridge, cutting paper, walking back into the garage, entering the cab, and re-opening the garage door are heard.