"No, to get down to the Tower room he would have had to pa.s.s my door, and he didn't, I am quite sure of that. And, anyway, M. Poirot, as I said just now, the man is as meek as a parson, I a.s.sure you."

"But yes, but yes," said Poirot soothingly, "I understand all that." He paused. "And you will not tell me the subject of your quarrel with Sir Reuben?"

The other's face turned a dark red.

"You'll get nothing out of me."

Poirot looked at the ceiling.

"I can always be discreet," he murmured, "where a lady is concerned."

Victor Astwell sprang to his feet.

"d.a.m.n you, how did you-what do you mean?"

"I was thinking," said Poirot, "of Miss Lily Margrave."

Victor Astwell stood undecided for a minute or two, then his colour subsided, and he sat down again.

"You are too clever for me, M. Poirot. Yes, it was Lily we quarrelled about. Reuben had his knife into her; he had ferreted out something or other about the girl-false references, something of that kind. I don't believe a word of it myself.

"And then he went further than he had any right to go, talked about her stealing down at night and getting out of the house to meet some fellow or other. My G.o.d! I gave it to him; I told him that better men than he had been killed for saying less. That shut him up. Reuben was inclined to be a bit afraid of me when I got going."

"I hardly wonder at it," murmured Poirot politely.

"I think a lot of Lily Margrave," said Victor in another tone. "A nice girl through and through."

Poirot did not answer. He was staring in front of him, seemingly lost in abstraction. He came out of his brown study with a jerk.

"I must, I think, promenade myself a little. There is a hotel here, yes?"

"Two," said Victor Astwell, "the Golf Hotel up by the links and the Mitre down by the station."

"I thank you," said Poirot. "Yes, certainly I must promenade myself a little."

The Golf Hotel, as befits its name, stands on the golf links almost adjoining the club house. It was to this hostelry that Poirot repaired first in the course of that "promenade" which he had advertised himself as being about to take. The little man had his own way of doing things. Three minutes after he had entered the Golf Hotel he was in private consultation with Miss Langdon, the manageress.

"I regret to incommode you in any way, Mademoiselle," said Poirot, "but you see I am a detective."

Simplicity always appealed to him. In this case the method proved efficacious at once.

"A detective!" exclaimed Miss Langdon, looking at him doubtfully.

"Not from Scotland Yard," Poirot a.s.sured her. "In fact-you may have noticed it? I am not an Englishman. No, I make the private inquiries into the death of Sir Reuben Astwell."

"You don't say, now!" Miss Langdon goggled at him expectantly.

"Precisely," said Poirot beaming. "Only to someone of discretion like yourself would I reveal the fact. I think, Mademoiselle, you may be able to aid me. Can you tell me of any gentleman staying here on the night of the murder who was absent from the hotel that evening and returned to it about twelve or half past?"

Miss Langdon's eyes opened wider than ever.

"You don't think-?" she breathed.

"That you had the murderer here? No, but I have reason to believe that a guest staying here promenaded himself in the direction of Mon Repos that night, and if so he may have seen something which, though conveying no meaning to him, might be very useful to me."

The manageress nodded her head sapiently, with an air of one thoroughly well up in the annals of detective logic.

"I understand perfectly. Now, let me see; who did we have staying here?"

She frowned, evidently running over the names in her mind, and helping her memory by occasionally checking them off on her fingertips.

"Captain Swann, Mr. Elkins, Major Blyunt, old Mr. Benson. No, really, sir, I don't believe anyone went out that evening."

"You would have noticed if they had done so, eh?"

"Oh, yes, sir, it is not very usual, you see. I mean gentlemen go out to dinner and all that, but they don't go out after dinner, because-well, there is nowhere to go to, is there?"

The attractions of Abbots Cross were golf and nothing but golf.

"That is so," agreed Poirot. "Then, as far as you remember, Mademoiselle, n.o.body from here was out that night?"

"Captain England and his wife were out to dinner."

Poirot shook his head.

"That is not the kind of thing I mean. I will try the other hotel; the Mitre, is it not?"

"Oh, the Mitre," said Miss Langdon. "Of course, anyone might have gone out walking from there."

The disparagement of her tone, though vague, was evident, and Poirot beat a tactful retreat.

Ten minutes later he was repeating the scene, this time with Miss Cole, the brusque manageress of the Mitre, a less pretentious hotel with lower prices, situated close to the station.

"There was one gentleman out late that night, came in about half past twelve, as far as I can remember. Quite a habit of his it was, to go out for a walk at that time of the evening. He had done it once or twice before. Let me see now, what was his name? Just for the moment I can't remember it."

She pulled a large ledger towards her and began turning over the pages.

"Nineteenth, twentieth, twenty-first, twenty-second. Ah, here we are. Naylor, Captain Humphrey Naylor."

"He had stayed here before? You know him well?"

"Once before," said Miss Cole, "about a fortnight earlier. He went out then in the evening, I remember."

"He came to play golf, eh?"

"I suppose so," said Miss Cole, "that's what most of the gentlemen come for."

"Very true," said Poirot. "Well, Mademoiselle, I thank you infinitely, and I wish you good day."

He went back to Mon Repos with a very thoughtful face. Once or twice he drew something from his pocket and looked at it.

"It must be done," he murmured to himself, "and soon, as soon as I can make the opportunity."

His first proceeding on reentering the house was to ask Parsons where Miss Margrave might be found. He was told that she was in the small study dealing with Lady Astwell's correspondence, and the information seemed to afford Poirot satisfaction.

He found the little study without difficulty. Lily Margrave was seated at a desk by the window, writing. But for her the room was empty. Poirot carefully shut the door behind him and came towards the girl.

"I may have a little minute of your time, Mademoiselle, you will be so kind?"

"Certainly."

Lily Margrave put the papers aside and turned towards him.

"What can I do for you?"

"On the evening of the tragedy, Mademoiselle, I understand that when Lady Astwell went to her husband you went straight up to bed. Is that so?"

Lily Margrave nodded.

"You did not come down again, by any chance?"

The girl shook her head.

"I think you said, Mademoiselle, that you had not at any time that evening been in the Tower room?"

"I don't remember saying so, but as a matter of fact that is quite true. I was not in the Tower room that evening."

Poirot raised his eyebrows.

"Curious," he murmured.

"What do you mean?"

"Very curious," murmured Hercule Poirot again. "How do you account, then, for this?"

He drew from his pocket a little sc.r.a.p of stained green chiffon and held it up for the girl's inspection.

Her expression did not change, but he felt rather than heard the sharp intake of breath.

"I don't understand, M. Poirot."

"You wore, I understand, a green chiffon dress that evening, Mademoiselle. This-" he tapped the sc.r.a.p in his fingers-"was torn from it."

"And you found it in the Tower room?" asked the girl sharply. "Whereabouts?"

Hercule Poirot looked at the ceiling.

"For the moment shall we just say-in the Tower room?"

For the first time, a look of fear sprang into the girl's eyes. She began to speak, then checked herself. Poirot watched her small white hands clenching themselves on the edge of the desk.

"I wonder if I did go into the Tower room that evening?" she mused. "Before dinner, I mean. I don't think so. I am almost sure I didn't. If that sc.r.a.p has been in the Tower room all this time, it seems to me a very extraordinary thing the police did not find it right away."

"The police," said the little man, "do not think of things that Hercule Poirot thinks of."

"I may have run in there for a minute just before dinner," mused Lily Margrave, "or it may have been the night before. I wore the same dress then. Yes, I am almost sure it was the night before."

"I think not," said Poirot evenly.

"Why?"

He only shook his head slowly from side to side.

"What do you mean?" whispered the girl.

She was leaning forward, staring at him, all the colour ebbing out of her face.

"You do not notice, Mademoiselle, that this fragment is stained? There is no doubt about it, that stain is human blood."

"You mean-"

"I mean, Mademoiselle, that you were in the Tower room after the crime was committed, not before. I think you will do well to tell me the whole truth, lest worse should befall you."

He stood up now, a stern little figure of a man, his forefinger pointed accusingly at the girl.

"How did you find out?" gasped Lily.

"No matter, Mademoiselle. I tell you Hercule Poirot knows. I know all about Captain Humphrey Naylor, and that you went down to meet him that night."

Lily suddenly put her head down on her arms and burst into tears. Immediately Poirot relinquished his accusing att.i.tude.

"There, there, my little one," he said, patting the girl on the shoulder. "Do not distress yourself. Impossible to deceive Hercule Poirot; once realize that and all your troubles will be at an end. And now you will tell me the whole story, will you not? You will tell old Papa Poirot?"

"It is not what you think, it isn't, indeed. Humphrey-my brother-never touched a hair of his head."

"Your brother, eh?" said Poirot. "So that is how the land lies. Well, if you wish to save him from suspicion, you must tell me the whole story now, without reservation."

Lily sat up again, pushing back the hair from her forehead. After a minute or two, she began to speak in a low, clear voice.

"I will tell you the truth, M. Poirot. I can see now that it would be absurd to do anything else. My real name is Lily Naylor, and Humphrey is my only brother. Some years ago, when he was out in Africa, he discovered a gold mine, or rather, I should say, discovered the presence of gold. I can't tell you this part of it properly, because I don't understand the technical details, but what it amounted to was this: "The thing seemed likely to be a very big undertaking, and Humphrey came home with letters to Sir Reuben Astwell in the hopes of getting him interested in the matter. I don't understand the rights of it even now, but I gather that Sir Reuben sent out an expert to report, and that he subsequently told my brother that the expert's report was unfavourable and that he, Humphrey, had made a great mistake. My brother went back to Africa on an expedition into the interior and was lost sight of. It was a.s.sumed that he and the expedition had perished.

"It was soon after that that a company was formed to exploit the Mpala Gold Fields. When my brother got back to England he at once jumped to the conclusion that these gold fields were identical with those he had discovered. Sir Reuben Astwell had apparently nothing to do with this company, and they had seemingly discovered the place on their own. But my brother was not satisfied; he was convinced that Sir Reuben had deliberately swindled him.

"He became more and more violent and unhappy about the matter. We two are alone in the world, M. Poirot, and as it was necessary then for me to go out and earn my own living, I conceived the idea of taking a post in this household and trying to find out if any connection existed between Sir Reuben and the Mpala Gold Fields. For obvious reasons I concealed my real name, and I'll admit frankly that I used a forged reference.

"There were many applicants for the post, most of them with better qualifications than mine, so-well, M. Poirot, I wrote a beautiful letter from the d.u.c.h.ess of Perthshire, who I knew had gone to America. I thought a d.u.c.h.ess would have a great effect upon Lady Astwell, and I was quite right. She engaged me on the spot.

"Since then I have been that hateful thing, a spy, and until lately with no success. Sir Reuben is not a man to give away his business secrets, but when Victor Astwell came back from Africa he was less guarded in his talk, and I began to believe that, after all, Humphrey had not been mistaken. My brother came down here about a fortnight before the murder, and I crept out of the house to meet him secretly at night. I told him the things Victor Astwell had said, and he became very excited and a.s.sured me I was definitely on the right track.