Dirk Bogarde digressed from his usual lightweight image to portray a smarmy murderer in Cast a Dark Shadow. He kills his first wife (Mona Washbourne), hoping to claim her inheritance. Surprise! The inheritance is a myth. Thus Bogarde sets his sights on barkeeper Margaret Lockwood, whom he knows to be heavily insured. But Lockwood is possessed of a naturally suspicious nature, making Bogarde's second murder plot a bit more delicate than his first. Cast a Dark Shadow is a too-literal adaptation of Janet Green's stage play Murder Mistaken.~ Hal Erickson, All Movie Guide