A well-plotted mystery with a very entertaining cast of characters, and Hastings's narration and perspective is particularly entertaining, because he never has any idea what is going on! Particular highlights are when Poirot comments that his very nature will help the case, as it will convince the murderer that they have no idea what is going on, and Hastings takes this as a compliment. Delightful, I really do enjoy Christie's very wryly funny style. This book has th  absolute classic 'Poirot gathers everyone into a room and explains the case to them, much to their amazement', and I love it, what a great trope, and 10/10 for creating it here, Christie.