The model Sonia Gluck is stabbed in mysterious ways while posing for a course in the model drawing. Inspector Roderick Alleyn is called in to investigate the murder in the artistic cirlce. However, before he can catch the killer, Roderick faces another problem: he falls in love with the prime suspect, painter Agatha Troy, which he has previously met on board a passenger ship in the South Pacific. Much to his disappointment, however, she shows no interest in him and belittles his life as a police officer. Supported by Inspector Fox, Roderick must soon find that he not only has to with murder but also with extortion.