A sister and her disturbed twin are implicated in a murder and a police detective must figure out which one's the killer.

Olivia de Havilland
as Terry Collins / Ruth Collins

Lew Ayres
as Dr. Scott Elliott

Thomas Mitchell
as Lt. Stevenson

Richard Long
as Rusty

Charles Evans
as Dist. Atty. Girard

Garry Owen
as Franklin

Lela Bliss
as Mrs. Didriksen

Lester Allen
as George Benson

Bess Flowers
as Nightclub Patron (uncredited)

Ida Moore
as Mrs. O'Brien (uncredited)
John Chard
Lemon Drops and Dopplegangers. The Dark Mirror is directed by Robert Siodmak and adapted to screenplay by Nunnally Johnson from a story by Vladimir Pozner. It stars Olivia de Havilland, Lew Ayres, Thomas Mitchell, Richard Long and Charles Evans. Music is by Dimitri Tiomkin and cinematography by ...
CinemaSerf
This is one of those films that you really have to pay close attention to - otherwise you can miss the nuances and menace created by the super performance from Olivia de Havilland - who plays two twins - in this whodunit with lots of twists. When "Dr. Petralta" is found stabbed through his heart - w...