Theo, a used-furniture dealer, and his lover, Vivien, like to enhance their love-making through dressing-up and role-playing. He pretends he's notorious murderer Dr. Hawley Harvey Crippen; she pretends she's either Crippen's wife, Belle Elmore, or Crippen's mistress, Ethel Le Neve. When they're not having sex, Theo and Vivien engage in a lot of bickering, but continue to live together above Theo's London shop. Entering their lives one day is Reingard, a female German photographer who's been observing the couple, whom she finds intriguing. Reingard moves into one of the rooms above the shop; under her influence, Theo begins to shed his Crippen persona in favor of that of another notorious figure, German flying ace Baron von Richthofen, a development which threatens to impact Theo's relationship with Vivien.