!"

"That's all very well," I objected, "but how are you going to decide
what is important, and what isn't? That always seems the difficulty to
me."

Poirot shook his head energetically. He was now arranging his moustache
with exquisite care.

"Not so. Voyons! One fact leads to another--so we continue. Does the
next fit in with that? A merveille! Good! We can proceed. This next
little fact--no! Ah, that is curious! There is something missing--a link
in the chain that is not there. We examine. We search. And that little
curious fact, that possibly paltry little detail that will not tally,
we put it here!" He made an extravagant gesture with his hand. "It is
significant! It is tremendous!"

"Y--es--"

"Ah!" Poirot shook his forefinger so fiercely at me that I quailed
before it. "Beware! Peril to the detective who says: 'It is so small--it
does not matter. It will not agree. I will forget it.' That way lies
confusion! Everything matters."

"I know. You always told me that. That's why I have gone into all the
details of this thing whether they seemed to me relevant or not."

"And I am pleased with you. You have a good memory, and you have given
me the facts faithfully. Of the order in which you present them, I say
nothing--truly, it is deplorable! But I make allowances--you are upset.
To that I attribute the circumstance that you have omitted one fact of
paramount importance."

"What is that?" I asked.

"You have not told me if Mrs. Inglethorp ate well last night."

I stared at him. Surely the war had affected the little man's brain.
He was carefully engaged in brushing his coat before putting it on, and
seemed wholly engrossed in the task.

"I don't remember," I said. "And, anyway, I don't see----"

"You do not see? But it is of the first importance."

"I can't see why," I said, rather nettled. "As far as I can remember,
she didn't eat much. She was obviously upset, and it had taken her
appetite away. That was only natural."

"Yes," said Poirot thoughtfully, "it was only natural."

He opened a drawer, and took out a small despatch-case, then turned to
me.

"Now I am ready. We will proceed to the chateau, and study matters on
the spot. Excuse me, mon ami, you dressed in haste, and your tie is on
one side. Permit me." With a deft gesture, he rearranged it.

"Ca y est! Now, shall we start?"

We hurried up the village, and turned in at the lodge gates. Poirot
stopped for a moment, and gazed sorrowfully