From the moment the stranger bursts into her antiquities shop in Rome, Lavinia Lake knows he is nothing but trouble. Announcing that he is a spy, Mr. Tobias March claims to be in pursuit of a killer and swears that Lavinia's life is in danger, but she is convinced that he is bent on destroying her. After being hustled all the way back to England, Lavinia vows to find a way to get back at him, never dreaming that Mr. March has actually been telling the truth.