"So Dorcas knows nothing about that black beard," said Poirot thoughtfully, as we walked out into the hall again.

"Do you think it is *THE one?" I whispered eagerly.

Poirot nodded.

"I do. You notice it had been trimmed?"

"No."

"Yes. It was cut exactly the shape of Mr. Inglethorp's, and I found one or two snipped hairs. Hastings, this affair is very deep."

"Who put it in the chest, I wonder?"

"Some one with a good deal of intelligence," remarked Poirot dryly. "You realize that he chose the one place in the house to hide it where its presence would not be remarked? Yes, he is intelligent. But we must be more intelligent. We must be so intelligent that he does not suspect us of being intelligent at all."

I acquiesced.

"There, mon ami, you will be of great assistance to me."

I was pleased with the compliment. There had been times when I hardly thought that Poirot appreciated me at my true worth.

"Yes," he continued, staring at me thoughtfully, "you will be invaluable."

This was naturally gratifying, but Poirot's next words were not so welcome.

"I must have an ally in the house," he observed reflectively.

"You have me," I protested.

"True, but you are not sufficient."

I was hurt, and showed it. Poirot hurried to explain himself.

"You do not quite take my meaning. You are known to be working with me. I want somebody who is not associated with us in any way."

"Oh, I see. How about John?"

"No, I think not."

"The dear fellow isn't perhaps very bright," I said thoughtfully.

"Here comes Miss Howard," said Poirot suddenly. "She is the very person. But I am in her black books, since I cleared Mr. Inglethorp. Still, we can but try."

With a nod that was barely civil, Miss Howard assented to Poirot's request for a few minutes' conversation.

We went into the little morning-room, and Poirot closed the door.

"Well, Monsieur Poirot," said Miss Howard impatiently, "what is it? Out with it. I'm busy."

"Do you remember, mademoiselle, that I once asked you to help me?"

"Yes, I do." The lady nodded. "And I told you I'd help you with pleasure-to hang Alfred Inglethorp."

"Ah!" Poirot studied her seriously. "Miss Howard, I will ask you one question. I beg of you to reply to it truthfully."

"Never tell lies," replied Miss Howard.

"It is this. Do you still believe that Mrs. Inglethorp was poisoned by her husband?"

"What do you mean?" she asked sharply. "You needn't think your pretty explanations influence me in the slightest. I'll admit that it wasn't he who bought strychnine at the chemist's shop. What of that? I dare say he soaked fly paper, as I told you at the beginning."

"That is arsenic-not strychnine," said Poirot mildly.

"What does that matter? Arsenic would put poor Emily out of the way just as well as strychnine. If I'm convinced he did it, it doesn't matter a jot to me *HOW he did it."

"Exactly. *IF you are convinced he did it," said Poirot quietly. "I will put my question in another form. Did you ever in your heart of hearts believe that Mrs. Inglethorp was poisoned by her husband?"

"Good heavens!" cried Miss Howard. "Haven't I always told you the man is a villain? Haven't I always told you he would murder her in her bed? Haven't I always hated him like poison?"

"Exactly," said Poirot. "That bears out my little idea entirely."

"What little idea?"

"Miss Howard, do you remember a conversation that took place on the day of my friend's arrival here? He repeated it to me, and there is a sentence of yours that has impressed me very much. Do you remember affirming that if a crime had been committed, and anyone you loved had been murdered, you felt certain that you would know by instinct who the criminal was, even if you were quite unable to prove it?"

"Yes, I remember saying that. I believe it too. I suppose you think it nonsense?"

"Not at all."

"And yet you will pay no attention to my instinct against Alfred Inglethorp."

"No," said Poirot curtly. "Because your instinct is not against Mr. Inglethorp."

"What?"

"No. You wish to believe he committed the crime. You believe him capable of committing it. But your instinct tells you he did not commit it. It tells you more-shall I go on?"

She was staring at him, fascinated, and made a slight affirmative movement of the hand.

"Shall I tell you why you have been so vehement against Mr. Inglethorp? It is because you have been trying to believe what you wish to believe. It is because you are trying to drown and stifle your instinct, which tells you another name--"

"No, no, no!" cried Miss Howard wildly, flinging up her hands. "Don't say it! Oh, don't say it! It isn't true! It can't be true. I don't know what put such a wild-such a dreadful- idea into my head!"

"I am right, am I not?" asked Poirot.

"Yes, yes; you must be a wizard to have guessed. But it can't be so-it's too monstrous, too impossible. It must be Alfred Inglethorp."

Poirot shook his head gravely.

"Don't ask me about it," continued Miss Howard, "because I shan't tell you. I won't admit it, even to myself. I must be mad to think of such a thing."

Poirot nodded, as if satisfied.

"I will ask you nothing. It is enough for me that it is as I thought. And I-I, too, have an instinct. We are working together towards a common end."

"Don't ask me to help you, because I won't. I wouldn't lift a finger to-to--" She faltered.

"You will help me in spite of yourself. I ask you nothing- but you will be my ally. You will not be able to help yourself. You will do the only thing that I want of you."

"And that is?"

"You will watch!"

Evelyn Howard bowed her head.

"Yes, I can't help doing that. I am always watching-always hoping I shall be proved wrong."

"If we are wrong, well and good," said Poirot. "No one will be more pleased than I shall. But, if we are right? If we are right, Miss Howard, on whose side are you then?"

"I don't know, I don't know--"

"Come now."

"It could be hushed up."

"There must be no hushing up."

"But Emily herself--" She broke off.

"Miss Howard," said Poirot gravely, "this is unworthy of you."

Suddenly she took her face from her hands.

"Yes," she said quietly, "that was not Evelyn Howard who spoke!" She flung her head up proudly. "*THIS is Evelyn Howard! And she is on the side of Justice! Let the cost be what it may." And with these words, she walked firmly out of the room.

"There," said Poirot, looking after her, "goes a very valuable ally. That woman, Hastings, has got brains as well as a heart."

I did not reply.

"Instinct is a marvellous thing," mused Poirot. "It can neither be explained nor ignored."

"You and Miss Howard seem to know what you are talking about," I observed coldly. "Perhaps you don't realize that I am still in the dark."

"Really? Is that so, mon ami?"

"Yes. Enlighten me, will you?"

Poirot studied me attentively for a moment or two. Then, to my intense surprise, he shook his head decidedly.

"No, my friend."

"Oh, look here, why not?"

"Two is enough for a secret."

"Well, I think it is very unfair to keep back facts from me."

"I am not keeping back facts. Every fact that I know is in your possession. You can draw your own deductions from them. This time it is a question of ideas."

"Still, it would be interesting to know."

Poirot looked at me very earnestly, and again shook his head.

"You see," he said sadly, "*YOU have no instincts."

"It was intelligence you were requiring just now," I pointed out.

"The two often go together," said Poirot enigmatically.

The remark seemed so utterly irrelevant that I did not even take the trouble to answer it. But I decided that if I made any interesting and important discoveries-as no doubt I should-I would keep them to myself, and surprise Poirot with the ultimate result.

There are times when it is one's duty to assert oneself.