Cast a Dark Shadow is a 1955 British Film Noir directed by Lewis Gilbert. The film was based on the play Murder Mistaken by Janet Green.
Edward "Teddy" Bare (Dirk Bogarde) kills his wealthy older wife, Monica, after she asks her lawyer, to change her will. To his chagrin, however, he discovers that he only inherits the mansion from a prior will, while her millions are left in trust to her only relative, her sister Dora, and that Edward will receive the money only after Dora dies. Edward later marries another well-off woman, Freda Jeffries (Margaret Lockwood), who is much less trusting than her predecessor, keeping tight control over her fortune. With a new bride who is no fool and Monica's lawyer, Phillip, making it clear that he suspects Edward, Edward is driven to contemplate murder once again.
This film features examples of:
- The Bluebeard: Edward marries women and then murders them for their fortune.
- Hoist by His Own Petard: Edward tampers the brakes of Charlotte's car after discovering that she is actually Dora, but when everybody discovers his crimes, he tries to flee his estate in his car, but the entrance is blocked by Charlotte's and Phillip's automobiles. With Phillip in pursuit, Edward switches to another vehicle, only to realise too late that he has taken Charlotte's. He loses control and drives off a cliff.
- Make It Look Like an Accident: Edward stages Monica's death to look as if she was accidentally asphyxiated while drunkenly trying to light a gas heater.
- The Reveal: Charlotte, the woman looking for a house, is actually Dora, Monica's sister.
- Vehicular Sabotage: Edward tampers the brakes of Charlotte's car after discovering that she is actually Dora, to inherit her money. It backfires on him when during a rush he ends up using said car.