"This alters everything, this does. I don't know whether you've realized it. Monsieur Poirot?"

Inspector Raglan had received a bad jolt. He was not deceived by Blunt's valiant lie any more than we had been. Our way back to the village was punctuated by his complaints.

"I think so, yes, I think so," said Poirot. "You see, me, I have been familiar with the idea for some time."

Inspector Raglan, who had only had the idea presented to him a short half-hour ago, looked at Poirot unhappily, and went on with his discoveries.

"Those alibis now. Worthless! Absolutely worthless. Got to start again. Find out what everyone was doing from nine-thirty onwards. Nine-thirty -- that's the time we've got to hang on to. You were quite right about the man Kent we don't release him yet awhile. Let me see now -- nineforty-five at the Dog and Whistle. He might have got there in a quarter of an hour if he ran. It's just possible that it was his voice Mr Raymond heard talking to Mr Ackroyd asking for money which Mr Ackroyd refused. But one thing's clear -- it wasn't he who sent the telephone message. The station is half a mile in the other direction -- over a mile and a half from the Dog and Whistle, and he was at the Dog and Whistle until about ten minutes past ten. Dang that telephone call! We always come up against it."

"We do indeed," agreed Poirot. "It is curious."

"Why should he have telephoned?"

"It's just possible that if Captain Paton climbed into his uncle's room and found him there murdered, he may have sent it. Got the wind up, thought he'd be accused, and cleared out. That's possible, isn't it?"

"May have had doubts if the old man was really dead. Thought he'd get the doctor up there as soon as possible, but didn't want to give himself away. Yes, I say now, how's that for a theory? Something in that, I should say."

The inspector swelled his chest out importantly. He was so plainly delighted with himself that any words of ours would have been quite superfluous.

Having dismissed the last patient, I strolled into the little room at the back of the house which I call my workshop I am rather proud of the home-made wireless set I turned out.

We arrived back at my house at this minute, and I hurried in to my surgery patients, who had all been waiting a considerable time, leaving Poirot to walk to the police station with the inspector.

"Oh! there you are, James," she said, with deep disapproval. "M. Poirot wants to see you."

Caroline hates my workroom. I have kept my tools there, and Annie is not allowed to wreak havoc with a dustpan and brush. I was just adjusting the interior of an alarm clock which had been denounced as wholly unreliable by the household, when the door opened and Caroline put her head in.

"Aha! my friend," said Poirot, coming forward and rubbing his hands. "You have not got rid of me so easily, you see!"

"In here?" said Caroline.

"That's what I said -- in here."

"Well," I said, rather irritably, for her sudden entrance had startled me and I had let go of a piece of delicate mechanism. "If he wants to see me, he can come in here."

"For the moment, yes. And you, you have seen all the patients?"

Caroline gave a sniff of disapproval and retired. She returned in a moment or two, ushering in Poirot, and then retired again, shutting the door with a bang.

"Yes." Poirot sat down and looked at me, tilting his egg-shaped head on one side, with the air of one who savours a very delicious joke.

"Finished with the inspector?" I asked.

"Precisement. I wish much to speak with her, so I send her the little note and make the appointment in your surgery. You are not annoyed with me?"

"You are in error," he said at last. "You have still one patient to see."

"Ah, not me, bien entendu. Me, I have the health magnificent. No, to tell you the truth, it is a little complot of mine. There is someone I wish to see, you understand -- and at the same time it is not necessary that the whole village should intrigue itself about the matter -- which is what would happen if the lady were seen to come to my house for it is a lady. But to you she has already come as a patient before."

"Not you?" I exclaimed in surprise.

"Miss Russell!" I exclaimed.

"On the contrary," I said. "That is, presuming I am allowed to be present at the interview?"

"But naturally! In your own surgery!"

"You know," I said, throwing down the pincers I was holding, "it's extraordinarily intriguing, the whole thing. Every new development that arises is like the shake you give to a kaleidoscope -- the thing changes entirely in aspect. Now, why are you so anxious to see Miss Russell?"

"There you go again," I grumbled. "According to you everything is obvious. But you leave me walking about in a fog."

"Perhaps you are right," I said at last. "All along I've felt that Flora was keeping back something -- so the truth, when it came, was subconsciously expected. It upset Inspector Raglan very much indeed, poor man."

"That -- perhaps no. But I was watching your face and you were not -- like Inspector Raglan -- startled and incredulous."

"You mock yourself at me. Take the matter of Mademoiselle Flora. The inspector was surprised -- but you -- you were not."

I thought for a minute or two.

"Surely it is obvious?" he murmured.

Poirot raised his eyebrows.

"Ah! pour {a oui The poor man must rearrange all his ideas. I profited by his state of mental chaos to induce him to grant me a little favour."

"What was that?"

Poirot shook his head genially to me.

Poirot took a sheet of notepaper from his pocket. Some words were written on it, and he read them aloud. "The police have, for some days, been seeking for Captain Ralph Paton, the nephew of Mr Ackroyd of Fernly Park, whose death occurred under such tragic circumstances last Friday. Captain Paton has been found at Liverpool, where he was on the point of embarking for America."

"I never dreamed of her being the thief," I expostulated.

Poirot beamed on me.

Every man has his hobby. I immediately drew Poirot's attention to my home-made wireless. Finding him sympathetic, I showed him one or two little inventions of my own -- trifling things, but useful in the house.

"But -- but it isn't true! He's not at Liverpool!"

"You have the intelligence so quick! No, he has not been found at Liverpool. Inspector Raglan was very loath to let me send this paragraph to the press, especially as I could not take him into my confidence. But I assured him most solemnly that very interesting results would follow its appearance in print, so he gave in, after stipulating that he was, on no account, to bear the responsibility."

I stared at him, dumbfounded.

"It is that you have really the love of the machinery," he said, after inspecting the debris of my labours.

He rose and came across to the bench.

He folded up the piece of paper again. "That, my friend, will be in the newspapers tomorrow morning."

"It beats me," I said at last, "what you expect to get out of that."

"You should employ your little grey cells," said Poirot gravely.

I stared at Poirot. He smiled back at me.

"Good-morning, mademoiselle," said Poirot. "Will you be seated? Dr Sheppard is so kind as to permit me the use of his surgery for a little conversation I am anxious to have with you."

"Indeed!"

"Decidedly," said Poirot, "you should be an inventor by trade, not a doctor. But I hear the bell -- that is your patient. Let us go into the surgery."

"Miss Russell -- I have news to give you."

Once before I had been struck by the remnants of beauty in the housekeeper's face. This morning I was struck anew. Very simply dressed in black, tall, upright and independent as ever, with her big dark eyes and an unwonted flush of colour in her usually pale cheeks, I realized that as a girl she must have been startlingly handsome.

"It seems a queer way of doing things, if you'll allow me to say so," she remarked.

Not a muscle of her face moved. She merely opened her eyes a trifle wider, and asked, with a tinge of defiance: "Well, what of it?"

"Charles Kent has been arrested at Liverpool."

Miss Russell sat down with her usual composure. If she felt any inward agitation, it did not display itself in any outward manifestation.

"Well I'm not particularly," said Miss Russell. "Who is this Charles Kent anyway?"

I looked at Poirot, full of my discovery, and he gave me an imperceptible nod. In answer to Miss Russell's question, he threw out his hands in a thoroughly French gesture.

But at that moment it came to me -- the resemblance that had haunted me all along, something familiar in the defiance of Charles Kent's manner. The two voices, one rough and coarse, the other painfully ladylike -- were strangely the same in timbre. It was of Miss Russell that I had been reminded that night outside the gates of Fernly Park.

"I thought you might be interested, that is all," he said mildly.

"He is a man, mademoiselle, who was at Fernly on the night of the murder."

"Fortunately for him, he has an alibi. At a quarter to ten he was at a public-house a mile from here."

"Really?"

"Lucky for him," commented Miss Russell.

"But we still do not know what he was doing at Fernly who it was he went to meet, for instance."

"I'm afraid I can't help you at all," said the housekeeper politely. "Nothing came to my ears. If that is all --" She made a tentative movement as though to rise. Poirot stopped her.

I saw the colour drain from the housekeeper's face, leaving it dead white. She leaned forward, her figure swaying.

"Miss Ackroyd has admitted that she was lying. She was never in the study at all that evening."

"But Miss Ackroyd said -- Miss Ackroyd said --"

"Then --"

"M. Poirot! M. Poirot! Oh, do believe me."

"Then it would seem that in this Charles Kent we have the man we are looking for. He came to Fernly, can give no account of what he was doing there --"

"It is not quite all," he said smoothly. "This morning fresh developments have arisen. It seems now that Mr Ackroyd was murdered, not at a quarter to ten, but before. Between ten minutes to nine, when Dr Sheppard left, and a quarter to ten."

She was leaning forward. That iron self-control was broken through at last. Terror and desperation was in her face.

"I can tell you what he was doing there. He never touched a hair of old Ackroyd's head -- he never went near the study. He didn't do it, I tell you."

Poirot got up and came to her. He patted her reassuringly on the shoulder.

"That Charles Kent is suspected of the crime? Yes, that is true. You alone can save him, by telling the reason for his being at Fernly."

For an instant suspicion flared up in her. "Is what you said true?"

"But yes -- but yes, I will believe. I had to make you speak, you know."

"In the summer-house, yes, I know."

"He came to see me." She spoke in a low, hurried voice. "I went out to meet him --"

"Mademoiselle, it is the business ofHercule Poirot to know things. I know that you went out earlier in the evening, that you left a message in the summer-house to say what time you would be there."

"How do you know?"

"Yes, I did. I had heard from him -- saying he was coming. I dared not let him come to the house. I wrote to the address he gave me and said I would meet him in the summerhouse, and described it to him so that he would be able to find it. Then I was afraid he might not wait there patiently, and I ran out and left a piece of paper to say I would be there about ten minutes past nine. I didn't want the servants to see me, so I slipped out through the drawing-room window. As I came back, I met Dr Sheppard, and I fancied that he would think it queer. I was out of breath, for I had been running. I had no idea that he was expected to dinner that night." She paused.

"Go on," said Poirot. "You went out to meet him at ten minutes past nine. What did you say to each other?"

"It's difficult. You see --"

"No one has ever known. It was long ago -- long ago -- down "i Kent. I was not married…"

"So you took the name of the county as a surname for him. I understand."

"Mademoiselle," said Poirot, interrupting her, "in this matter I must have the whole truth. What you tell us need never go beyond these four walls. Dr Sheppard will be discreet, and so shall I. See, I will help you. This Charles Kent, he is your son, is he not?" She nodded. The colour had flamed into her cheeks.

"I got work. I managed to pay for his board and lodging. I never told him that I was his mother. But he turned out badly, he drank, then took to drugs. I managed to pay his passage out to Canada. I didn't hear of him for a year or two. Then, somehow or other, he found out that I was his mother. He wrote asking me for money. Finally, I heard from him back in this country again. He was coming to see me at Fernly, he said. I dared not let him come to the house. I have always been considered so -- so very respectable. If anyone got an inkling -- it would have been all up with my post as housekeeper. So I wrote to him in the way I have just told you."

"What time was that?"

"I think that is all," he said thoughtfully.

"Straight out the same way he came, by the path that joined the drive just inside the lodge gates."

"I went back to the house. Major Blunt was walking up and down the terrace smoking, so I made a detour to get round to the side door. It was just then on half-past nine, as I tell you."

"Yes. I wondered if something could be done. He was not a bad boy -- before he took to drugs."

"Yes, he was waiting for me when I got there. He was very rough and abusive. I had brought with me all the money I had, and I gave it to him. We talked a little, and then he went away."

"Which way did he go?"

Poirot nodded again. He made a note or two in a microscopic pocketbook.

"And in the morning you came to see Dr Sheppard?"

"I see," said Poirot. "Now let us go on with the story. He came that night to the summerhouse?"

Poirot nodded. "And you, what did you do?"

"It must have been between twenty and twenty-five minutes past nine. It was not yet half-past when I got back to the house."

"It may come to that. But let us not be in a hurry. Let us proceed slowly, with due order and method. Charles Kent is not yet formally charged with murder. Circumstances may arise which will render your story unnecessary."

*Ought I -?" she hesitated. "Ought I to tell all this to Inspector Raglan?"

Miss Russell rose.

"Thank you very much, M. Poirot," she said. "You have been very kind -- very kind indeed. You -- you do believe me, don't you? That Charles had nothing to do with this wicked murder!"

"There seems no doubt that the man who was talking to Mr Ackroyd in the library at nine-thirty could not possibly have been your son. Be of good courage, mademoiselle. All will yet be well."

"So that's that," I said. "Every time we come back to Ralph Paton. How did you manage to spot Miss Russell as the person Charles Kent came to meet? Did you notice the resemblance?"

Miss Russell departed. Poirot and I were left together.

"I had connected her with the unknown man long before we actually came face to face with him. As soon as we found that quill. The quill suggested dope, and I remembered your account of Miss Russell's visit to you. Then I found the article on cocaine in that morning's paper. It all seemed very clear. She had heard from someone that morning -- someone addicted to drugs, she read the article in the paper, and she came to ask you a few tentative questions. She mentioned cocaine, since the article in question was on cocaine. Then, when you seemed too interested, she switched hurriedly to the subject of detective stories and untraceable poisons. I suspected a son or a brother, or some other undesirable male relation. Ah! but I must go. It is the time of the lunch."

"Stay and lunch with us," I suggested.

"Not again today. I should not like to force Mademoiselle Caroline to adopt a vegetarian diet two days in succession."

Poirot shook his head. A faint twinkle came into his eye.

It occurred to me that there was not much which escaped Hercule Poirot.