After finishing I had a stupid smile on my face, and I was thinking how anyone can be so brilliant to make a reader an utter fool. I might suggest this is so far the best of Christie's work I've read. I was sure I had solved the case and then she reveals such clues that I change my mind and turn my attention elsewhere. Well, turns out I was caught completely off guard and the solution was something I would have never guessed. I mean, I remember seeing a TV adaptation of this and I still didn't realize!