The Mafu Cage

The Mafu Cage (also released as My Sister, My Love, Deviation and Don't Ring the Doorbell)[2] is a 1978 American psychological horror film[3][4] directed by Karen Arthur, and starring Carol Kane and Lee Grant. Its plot follows two sisters, both the daughters of a late anthropologist, residing in a dilapidated Los Angeles mansion: one, an astronomer, and the other, a dysfunctional eccentric who keeps and tortures a variety of monkeys and other primates.

Arthur worked with screenwriter Don Chastain to loosely adapt Eric Westphal's play Toi et Tes Nuages, which she had seen in Paris in 1975.[5] The finished product premiered at Cannes in 1978.[6]