In Haddonfield, Illinois, the nine years old Michael Meyers is raised by a dysfunctional family: his mother Deborah is a stripper in a night-club; his foster father Ronnie is an alcoholic bum; his sister Judith is a easy girl; and he is connected to his baby sibling. On October, 31st, after an incident in school where he is bullied by a schoolmate, Michael overhears the conversation of the principal and the psychiatric Dr. Samuel Loomis with his mother. They had found pictures of Michael torturing animals in his backpack and Dr. Loomis would like to send Michael for psychiatric evaluation believing that the boy is deranged. This revelation triggers Michael that escapes from the school and kills the bully, Ronnie, Judith's boyfriend Steve Haley and his sister Judith. Michael is held in custody in the Smith's Grove Sanatorium under the treatment of Dr. Loomis. Eleven months later, during the visit of his mother, Michael kills his nurse and his stressed mother commits suicide. Fifteen years later, Michael escapes from the mental institution leaving bloodshed behind, and heads to Haddonfield in the Halloween's night.
