Surprise Guilty Party

Someone clever has done it--but whom?
Gather everyone, all in a room
Who committed the crime
Will admit it in time
Though it's never the one you assume.



Whodunnits and mysteries often employ a penultimate scene where the detective gathers all the suspects together. Here Nick and Nora Charles hold a dinner party in The Thin Man (W. S. Van Dyke; 1934). David Cairns came up with the title, and he's also guilty of suggesting the scene.