If it weren't for the frequent pauses for morbid pseudo-poetic philosophising, this might be a Warners melodrama, Bette Davis vintage. (Indeed, it bears some resemblance to Bernhardt's A Stolen Life.) Desperate, impoverished del Río murders her wealthy, unsympathetic, identical twin sister, and adopts her identity, only to experience doubts over abandoning her own loyal lover and confusion over the hitherto unknown facets of her sibling's existence. Fine noir-style camerawork and a taut if over-schematic narrative are let down by clumsy dialogue and the star's hammy double performance. Hitchcock might have enjoyed the fascination with guilt and its transference, but not, probably, the execution.