An innocent children's Halloween party is being held in a small town near London, during the course of the party a child makes an innocuous remark about witnessing a murder some years back, she did not know at that time that it was murder but now she knows. The child is found murdered after the party ends. Did someone got spooked or did some malignant outsider step in the house and kill her? Ariadne Oliver, prolific mystery novel author and Poirot's friend was also present at the party and she believes that some malevolent person is behind the killing of the child. So, she goes to London to meet Poirot and once again Poirot has to use his little gray cells to solve this most perplexing murder.
The case gets more convoluted as everyone believes that the child was a habitual liar and only made up the story of witnessing a murder to get attention. Poirot and Ariadne though unsure have the gut feeling that the child is not lying and there is something odd about the whole affair. As more murders follow they become more convinced that someone present at the party murdered the child on overhearing her.
With a truckload of suspects, multiple murders, and two of Christie's most well liked characters in Poirot and Ariadne - this becomes a very enjoyable read. The mystery itself is fairly clued and it is not very difficult to work out the identity of the murderer. The books is not too long and not short, just around 300 odd pages and one breezes through the entire thing in < 2 days. Characterization is weak part of the book with so many characters and names squeezed in between, it is difficult to make out who is who, if not a prominent actor in the story. We also see a mellow version of Poirot, who is nearing the end of his illustrious career and is battling old age.
I expected Some humor and funny scenes in the book because of the presence of Ariadne Oliver and Poirot but there were very few for me to recall. This is one of the better Christie books, but not to close to her earlier brilliant works.