"Deduce, Poirot, from the following facts Here is a young lady, richly dressed-fashionable hat, magnificent furs. She is coming along slowly, looking up at the houses as she goes. Unknown to her, she is being shadowed by three men and a middle-aged woman. They have just been joined by an errand boy who points after the girl, gesticulating as he does so. What drama is this being pla-yed? Is the girl a crook, and are the shadowers detectives preparing to arrest her? Or are they the scoundrels, and are they plotting to attack an innocent victim? What does the great detective say?