Poirot stopped my eager questions with an airy gesture of the hand.

“Not now, I pray you. Let us not confuse the mind. And observe that Peerage⁠—how you have replaced him! See you not that the tallest books go in the top shelf, the next tallest in the row beneath, and so on. Thus we have order, method , which, as I have often told you, Hastings⁠—”

“Exactly,” I said hastily, and put the offending volume in its proper place.

Lord Yardly turned out to be a cheery, loud-voiced sportsman with a rather red face, but with a good-humoured bonhomie about him that was distinctly attractive and made up for any lack of mentality.

“Extraordinary business this, Monsieur Poirot. Can’t make head or tail of it. Seems my wife’s been getting odd kind of letters, and that this Miss Marvell’s had ’em too. What does it all mean?”