I have to admit that for much of the time I spent reading this, I considered it a three star read. I mean it's entertaining enough - Christie's prose is as smooth as ever, and if I don't quite find Poirot retiring to a little country village to grow marrows especially convincing, it's still amusing. Then came the ending, and suddenly the whole book rearranged itself into something startlingly clever. I am not startlingly clever, at least not with mysteries. Most of the time I never know whodunit until I'm told. But just as Poirot started the final explanation the light dawned, and I was almost afraid to read further, in case the dawning wasn't true, and the murderer more prosaic than they were. (You see I am trying to preserve the mystery myself, lest this review spoil a 90+ year old book.) No wonder this is put forward as one of the finest in the genre...