Trilogy of Terror (1975)

Three discrete horror stories are presented, one of the few things tying them all together being each starring Karen Black in dual roles, that duality explicit in one instance and more veiled in the others. In "Julie", college student Chad Foster, a player, laments the lack of attractive females on campus.

Without having had the thought before, he wonders what his Plain Jane English professor Julie Eldredge would be like sexually underneath her frumpy clothes. He begins a campaign of lies and manipulation to get Julie into a compromising position. In "Millicent and Therese", spinsterish Millicent Lorrimore goes on a campaign to convince key people in her sexually provocative twin sister Therese Lorrimore's life that Therese is evil, guided by Satan. That evilness, according to Millicent, includes having committed murder and initiated incest with their father. Among those Millicent tries to convince are Therese's boyfriend, Thomas Anmar, and their family physician, Dr. Chester Ramsey. Millicent is planning to kill Therese to stop the evil if no one else will do anything. The question becomes if Millicent can convince anyone to help her before it's too late. And in "Amelia", the title character has just purchased a Zuni fetish doll as a birthday gift for her anthropologist professor boyfriend, Arthur Breslow, with who she is planning to celebrate this evening instead of her weekly routine of spending the evening with her overbearing and hypercritical mother. The chain on the doll falls off, something that the insert that came with the doll warns against happening. That act leads to a fundamental change in the doll and by association Amelia and her relationship with her mother.