It's been a while since we've had Mark on our show, but we couldn't pass up the opportunity to fawn over his new book, Agatha Christie's Poirot: The Greatest Detective in the World. This also gave us as good an excuse as any to chatter on about Poirot for an hour or so.... If you feel so inclined (and we wager you will), go to https://bookshop.org to (pre-)order a copy for yourself, if you don't have one already.