Also known as Psycho Sisters and The Sibling, this would-be Hitchcockian thriller might have passed muster as a TV movie or an episode of, say, Night Gallery. Presented as a proper feature, it’s woefully insufficient. The characterizations are shallow, the story is far-fetched, and the suspense scenes are underwhelming. So while some of the acting meets baseline professional standards, the silly script undercuts the performances. After a jumbled opening sequence involving a car crash, a police chase, and the revelation of a murky criminal conspiracy, the story proper gets underway. Following the death of her husband, bereaved Brenda (Susan Strasberg) moves in with her sister, Millie (Faith Domergue). Recently released from a sanitarium, Millie has a prescription for anti-psychotic medication, and she slips her pills into Brenda’s meals, making it easier for her to gaslight Brenda. Turns out Millie wants Brenda declared insane so Millie can acquire wealth belonging to Brenda’s late husband. Also thrown into the mix is a simpleton handyman who menaces Brenda, a beach-bum stud who romances Brenda, and intrepid cops sniffing around the situation because they detect criminal activity. Bouncing between relatively grounded scenes of sibling rivalry and cartoonish horror-movie beats (hallucinatory visions of corpses, etc.), the flick trudges along pointlessly from one credibility-stretching plot twist to the next until the whole scenario feels ridiculous. Ultimately, So Evil, My Sister is noteworthy only as an early credit for both actor John Ashton and cinematographer Dean Cundey, even though Cundey’s work here bears none of the confident style one normally associates with his name.
So Evil, My Sister: LAME