Ivy Lexton (Joan Fontaine) is a woman who lets nothing get in the way of her desires. She's balancing a loveless marriage and a fizzling affair when she meets the affable and affluent Miles Rushworth (Herbert Marshall). He becomes her new obsession, but he refuses to get involved with a married woman. Not easily dissuaded, Ivy plans to murder her husband, Jervis (Richard Ney), and frame her lover, Roger (Patric Knowles), to make herself available to Miles.