"I couldn't rightly say, sir; it was shut but I couldn't say whether it was bolted or not."

"When you finally left the room, did Mrs. Inglethorp bolt the door after you?"

"No, sir, not then, but I expect she did later. She usually did lock it at night. The door into the passage, that is."

"Did you notice any candle grease on the floor when you did the room yesterday?"

"Candle grease? Oh, no, sir. Mrs. Inglethorp didn't have a candle, only a reading-lamp."

"Then, if there had been a large patch of candle grease on the floor, you think you would have been sure to have seen it?"

"Yes, sir, and I would have taken it out with a piece of blotting-paper and a hot iron."

Then Poirot repeated the question he had put to Dorcas:

"Did your mistress ever have a green dress?"

"No, sir."

"Nor a mantle, nor a cape, nor a-how do you call it?-a sports coat?"

"Not green, sir."

"Nor anyone else in the house?"

Annie reflected.

"No, sir."

"You are sure of that?"

"Quite sure."

"Bien! That is all I want to know. Thank you very much."

With a nervous giggle, Annie took herself creakingly out of the room. My pent-up excitement burst forth.

"Poirot," I cried, "I congratulate you! This is a great discovery."

"What is a great discovery?"

"Why, that it was the coco and not the coffee that was poisoned. That explains everything! Of course it did not take effect until the early morning, since the coco was only drunk in the middle of the night."

"So you think that the coco-mark well what I say, Hastings, the coco-contained strychnine?"

"Of course! That salt on the tray, what else could it have been?"

"It might have been salt," replied Poirot placidly.

I shrugged my shoulders. If he was going to take the matter that way, it was no good arguing with him. The idea crossed my mind, not for the first time, that poor old Poirot was growing old. Privately I thought it lucky that he had associated with him some one of a more receptive type of mind.

Poirot was surveying me with quietly twinkling eyes.

"You are not pleased with me, mon ami?"

"My dear Poirot," I said coldly, "it is not for me to dictate to you. You have a right to your own opinion, just as I have to mine."

"A most admirable sentiment," remarked Poirot, rising briskly to his feet. "Now I have finished with this room. By the way, whose is the smaller desk in the corner?"

"Mr. Inglethorp's."

"Ah!" He tried the roll top tentatively. "Locked. But perhaps one of Mrs. Inglethorp's keys would open it." He tried several, twisting and turning them with a practiced hand, and finally uttering an ejaculation of satisfaction. "Viola! It is not the key, but it will open it at a pinch." He slid back the roll top, and ran a rapid eye over the neatly filed papers. To my surprise, he did not examine them, merely remarking approvingly as he relocked the desk: "Decidedly, he is a man of method, this Mr. Inglethorp!"

A "man of method" was, in Poirot's estimation, the highest praise that could be bestowed on any individual.

I felt that my friend was not what he had been as he rambled on disconnectedly:

"There were no stamps in his desk, but there might have been, eh, mon ami? There might have been? Yes"-his eyes wandered round the room-"this boudoir has nothing more to tell us. It did not yield much. Only this."

He pulled a crumpled envelope out of his pocket, and tossed it over to me. It was rather a curious document. A plain, dirty looking old envelope with a few words scrawled across it, apparently at random. The following is a facsimile of it.