Investigating a spy-ring, Lt. Colin Race comes to Wilbraham Crescent, where he literally bumps into agency typist Sheila Webb, as she comes flying out of number 19, the home of blind receptionist Millicent Pebmarsh. Sheila has discovered the body of a man whose identity proves hard to confirm, surrounded by four clocks, stopped at the same time. Miss Pebmarsh does not know the man and did not ask for the services of Sheila, who is the initial chief suspect. However, as Poirot is brought in to assist Inspector Hardcastle in the case, and the murderer strikes again, Poirot comes to realize that the man was killed elsewhere and brought to Miss Pebmarsh's house. The neighbors claim to have seen nothing but Poirot believes one of them may have had a secret which was worth killing for and sets out to unmask them, as well as explaining the significance, if any, of the clocks. At the same time, Colin solves his investigation with Poirot's help.