Plot

It was on Halloween night that a young Michael Myers inexplicably slaughtered his slutty older sister. Fifteen later, he escapes a mental hospital and returns home. Spotting a scholarly looking teenager, Laurie, the deranged psychopath Michael lusts after her and stalks her. Finding her trampy friends, Annie and Lynda engaging in carnal acts with their boyfriends on Halloween eve, just as his sister did years ago, sets Michael off.