Conceived as a parody of the slasher movie, The Slumber Party Massacre was eventually shot as a straightforward horror, leading to some uniquely dark humour both intended and otherwise, and was the first film in what would become a long running series, blazing a trail for female filmmakers as the first horror franchise to be entirely written and directed by women. It's going to be the slumber party to end all slumber parties. With her parents away, Trish (Michele Michaels) is planning a weekend of high jinks fun for her high school basketball team friends - a slumber party at her house. She's not sure if she wants to invite the newly arrived and talented Valerie (Robin Stille) but someone who is definitely coming is Russ Thorn. Locked up in a mental institution since 1969, Thorn, the nastiest of the driller killer psychos, has escaped and is heading back to town intent on more bloody mayhem. This night no one's going to get much sleep - there's potato chips, drinks, dope, severed heads, blood and gore-a-plenty.