I was rather surprised, if not disappointed, to learn only after I started reading Murder in the Mews, that this book in the Poirot series in fact consists out of four totally independent stories. Even for Agatha Christie I would say that four mysteries in less than 350 pages is a bit of a stretch.
All four of them were - of course - very nice and again unique examples of Christies' endless wittiness, but I would rather have enjoyed them wrapped in longer stories.