Three and a half stars, rounding up to four. It took me a while to get through this, because I wasn't that interested in any of the characters - there seemed an awful lot of them, and so many red herrings that the book felt kind of scattered. I liked it, but I wasn't terribly excited about it... it seemed a solid three star read to me.

Then came the end. I said I wasn't that interested in any of the characters, but there was one. Bits had been seeded through the book that were moderately interesting, concerning this person, and the book concludes with a letter they write to Poirot explaining how and why they performed their crimes. And that short letter is a masterpiece of characterisation, and makes the entire book more entertaining for the villain alone. Those two or three pages dragged up the rating all on their own. If only the rest of it had been so compelling!