6-year-old Michael stabs his sister Judith to death on Halloween night, 1963 and he escapes 15 years later from Smith's Grove Sanitarium where he begins stalking a babysitter named Laurie Strode on Halloween and killing off her friends. Michael is ultimately stopped from killing Laurie by his psychiatrist, Dr. Samuel Loomis who shoots Michael six times off the house balcony though he escapes into the night The film explains that Laurie and Michael are siblings and it's why he is stalking her. Picking up where Halloween ended, Michael finds Laurie at Haddonfield Memorial Hospital where he begins killing various staff members who stand in his way. In the end, Loomis blows himself and Michael up in a gas-filled room while Michael collapses in the hallway engulfed in flames