Marnie Edgar is a first-class bookkeeper and the apple of her employers' eyes. She happens also to be a compulsive thief who has taken her last employer, Sidney Strutt, to the cleaners before disappearing into thin air. But with Mark Rutland, she attempts robbery once too often. He forces her to marry him, and out of love for her, uncovers the mysteries of her past that contribute to her penchant for taking other people's money.