A perplexed girl thinks she might have killed someone! Three single girls shared the same London flat. The first worked as a secretary; the second was an artist; the third who came to Poirot for help disappeared convinced she was a murderer. Now there were rumours of revolvers flick-knives & blood stains. But without hard evidence it would take all Poirots tenacity to establish whether the third girl was guilty innocent or insane!