Lady Rose Summer, the wayward Edwardian debutante who keeps getting mixed up in disreputable adventures, would swear she is not a jealous woman. After all, she knows her engagement to private detective Captain Harry Cathcart is only a ploy to keep her parents from shipping her off to India. But then Harry's latest client, Dolores Duval—a vision of curves with a seductive French accent—starts appearing everywhere at his side. In a fit of rage, Rose threatens Dolores, only to be found the very next day, standing over her dead body. The newspapers rush to convict her, but can Harry and Detective Superintendent Kerridge clear her name?