Marnie is about a young woman who makes a living by embezzling her employers' funds, moving on, and changing her identity.

She is finally caught in the act by one of her employers, a young widower named Mark Rutland, who blackmails her into marriage.

Two shocking events near the end of the story send the troubled woman to the brink of suicide, and she must eventually face the trauma from her past that is the root cause of her behaviour.

The book was the basis for Alfred Hitchcock's suspense film Marnie (1964), in which the setting was changed from England to the United States.

The co-production with the Metropolitan Opera had its American premiere on 19 October 2018, starring Isabel Leonard in the title role.