Someone has shot and killed Lowe Hammle and everyone at his 22 room apartment is a suspect. The reasons are as varied as the number of people there. There is Dr. Garden, whose son Floyd was killed at the track in a mysterious way which is thought to be a suicide. There is Mrs. Fenwicke-Ralston who was supposed to complete a deal on a horse. There is the blackmailing Nurse Beeton and the niece Zalia, who knows that Uncle is trying to break up her relationship with Woode. Since there is no powder marks on the body, Vance knows that it is murder and believes that a woman did the job. But he has to find the killer and the motive.