This Hercule Poirot book was weird. I'm still not sure that I understand the ending. I learned afterward that this was an amalgamation of short stories that was then loosely tied together with this criminal organization of four people bent on world domination. However, it did mean that this book was more fast-paced than the others, with several mysteries solved over the course of the book. It also has some great Captain Hastings-Poirot back-and-forths.

'"My dear Poirot, you know now what the enemy thinks of us. He appears to have a grossly exaggerated idea of your bran power, and to have absurdly underrated mine, but I do not see how we are better off for knowing this." Poirot chuckled in rather an offensive way.'

'"I hope that they will not succeed in massacring Hastings also, that is all. That would annoy me greatly." I interrupted this cheerful conversation to remark that I had no intention of letting myself be massacred.'