Useless to inquire at Agency. They will never have heard of her. Find out what vehicle took her up to Hunter’s Lodge when she first arrived there.

Though mystified, I was obedient. The means of transport in Elmer’s Dale were limited. The local garage had two cars, and there were two station flies. None of these had been requisitioned on the date in question. I may also mention that inquiries at the Agency in London bore out Poirot’s prognostication. No such woman as “Mrs. Middleton” had ever been on their books. They had received the Hon. Mrs. Havering’s application for a housekeeper, and had sent her various applicants for the post. When she sent them the engagement fee, she omitted to mention which woman she had selected.

It is suggested that the reader pause in his perusal of the story at this point, make his own solution of the mystery—and then see how close he comes to that of the author—The Editors.

Somewhat crestfallen, I returned to London. I found Poirot established in an armchair by the fire. He greeted me with much affection.

Mon ami Hastings! But how glad I am to see you! Veritably I have for you a great affection! And you have enjoyed yourself? You have run to and fro with the good Japp? You have interrogated and investigated to your heart’s content?”

“Poirot,” I cried, “the thing’s a dark mystery! It will never be solved.”

“It is true that we are not likely to cover ourselves with glory over it.”

“No, indeed. It’s a hard nut to crack.”

“Oh, as far as that goes, me, I am very good at cracking the nuts! A veritable squirrel! It is not that which embarrasses me. I know well enough who killed Mr. Harrington Pace.”

“You know? How did you find out?”