** spoiler alert ** 
 Big Four, Agatha Christie Far fetched, but enjoyable. A cabal has formed (if you can't guess how by how many you will have to read the book) and they have spread their malevolent influence over all the globe. By accident one of their victims escapes and reaches the sanctuary of Poirot's domicile. After gasping out a warning of immanent destruction, he dies. Now it is up to the matchless detective to save the poor unsuspecting world from chaos, which he does.