Well, damn it. For ninety percent of this book I was sure that - against all odds, because even I'm not optimistic enough to think that it would happen again - I'd twigged who the murderer was before Poirot did. I may not have known why, but I was certain as to who. Looking back, however, there's a very clear red herring that I fell for hook, line, and sinker. Suckered again.

Somewhere Agatha Christie is laughing her long-dead head off.