This was a re-read for me; I'd read it many years ago. It's the first Poirot story. An okay read, a bit contrived. I usually like Christie's books as a whole.
I've become somewhat interested in collecting first editions of books. So, this nonfiction title was a good pick for me. It discusses what to look for as far as the condition of the book (mostly hardbacks, but also some paperbacks) and how to discern if it's a first edition. To a lesser extent, the book goes into how to judge if authors are collectable and/or have staying power. Enjoyable read for me.