The Dark Mirror (1946) Movie Review, Cast & Crew, Film Summary

A precursor to Dead Ringers, this bright little nugget of a film is essentially a one-woman show for Olivia De Havilland, who plays twins Terry and Ruth, one of whom is a goody-two-shoes and the other of whom is a pathological murderer. Only heroically weedy psychologist Lew Ayres can find which is which, bravely revealing the killer with Rorschach blots and free-association sessions. Robert Siodmak’s direction is surprisingly bland, so it’s chiefly interesting for De Havilland’s performances, relying on her ability to play fifty-seven varieties of sweetness and light, before her carefully delineated divergences in characterization become more and more telling, building to the climactic revelation of pure madness.