Chapter VIII: Part 8

"Yes, you are older. And by that I do not mean that the wrinkles and the crows' feet are coming. When I first saw you, Mademoiselle, you were a looker-on at life. You had the quiet, amused look of one who sits back in the stalls and watches the play."

"And now?"

"Now, you no longer watch. It is an absurd thing, perhaps, that I say here, but you have the wary look of a fighter who is playing a difficult game."

"My old lady is difficult sometimes," said Katherine, with a smile; "but I can assure you that I don't engage in deadly contests with her. You must go down and see her some day, Monsieur Poirot. I think you are one of the people who would appreciate her pluck and her spirit."

There was a silence while the waiter deftly served them with chicken _en casserole_. When he had departed, Poirot said:

"You have heard me speak of my friend Hastings?--he who said that I was a human oyster. _Eh bien_, Mademoiselle, I have met my match in you. You, far more than I, play a lone hand."

"Nonsense," said Katherine lightly.

"Never does Hercule Poirot talk nonsense. It is as I say."

Again there was a silence. Poirot broke it by inquiring:

"Have you seen any of our Riviera friends since you have been back, Mademoiselle?"

"I have seen something of Major Knighton."

"A-ha! Is that so?"

Something in Poirot's twinkling eyes made Katherine lower hers.

"So Mr. Van Aldin remains in London?"

"Yes."

"I must try to see him to-morrow or the next day."

"You have news for him?"

"What makes you think that?"

"I--wondered, that is all."

Poirot looked across at her with twinkling eyes.

"And now, Mademoiselle, there is much that you wish to ask me, I can see that. And why not? Is not the affair of the Blue Train our own 'Roman Policier'?"

"Yes, there are things I should like to ask you."

"_Eh bien?_"

Katherine looked up with a sudden air of resolution.

"What were you doing in Paris, Monsieur Poirot?"

Poirot smiled slightly.

"I made a call at the Russian Embassy."

"Oh."

"I see that that tells you nothing. But I will not be a human oyster. No, I will lay my cards on the table, which is assuredly a thing that oysters do not do. You suspect, do you not, that I am not satisfied with the case against Derek Kettering?"

"That is what I have been wondering. I thought, in Nice, that you had finished with the case."

"You do not say all that you mean, Mademoiselle. But I admit everything. It was I--my researches--which placed Derek Kettering where he is now. But for me the Examining Magistrate would still be vainly trying to fasten the crime on the Comte de la Roche. _Eh bien_, Mademoiselle, what I have done I do not regret. I have only one duty--to discover the truth, and that way led straight to Mr. Kettering. But did it end there? The police say yes, but I, Hercule Poirot, am not satisfied."

He broke off suddenly. "Tell me, Mademoiselle, have you heard from Mademoiselle Lenox lately?"

"One very short, scrappy letter. She is, I think, annoyed with me for coming back to England."

Poirot nodded.

"I had an interview with her the night that Monsieur Kettering was arrested. It was an interesting interview in more ways than one."

Again he fell silent, and Katherine did not interrupt his train of thought.

"Mademoiselle," he said at last, "I am now on delicate ground, yet I will say this to you. There is, I think, some one who loves Monsieur Kettering--correct me if I am wrong--and for her sake--well--for her sake I hope that I am right and the police are wrong. You know who that some one is?"

There was a pause, then Katherine said:

"Yes--I think I know."

Poirot leant across the table towards her.

"I am not satisfied, Mademoiselle; no, I am not satisfied. The facts, the main facts, led straight to Monsieur Kettering. But there is one thing that has been left out of account."

"And what is that?"

"The disfigured face of the victim. I have asked myself, Mademoiselle, a hundred times, 'Was Derek Kettering the kind of man who would deal that smashing blow after having committed the murder?' What end would it serve? What purpose would it accomplish? Was it a likely action for one of Monsieur Kettering's temperament? And, Mademoiselle, the answer to these questions is profoundly unsatisfactory. Again and again I go back to that one point--'why?' And the only things I have to help me to a solution of the problem are these."

He whipped out his pocket-book and extracted something from it which he held between his finger and thumb.

"Do you remember, Mademoiselle? You saw me take these hairs from the rug in the railway carriage."

Katherine leant forward, scrutinizing the hairs keenly.

Poirot nodded his head slowly several times.

"They suggest nothing to you, I see that, Mademoiselle. And yet--I think somehow that you see a good deal."

"I have had ideas," said Katherine slowly, "curious ideas. That is why I ask you what you were doing in Paris, Monsieur Poirot."

"When I wrote to you--"

"From the Ritz?"

A curious smile came over Poirot's face.

"Yes, as you say, from the Ritz. I am a luxurious person sometimes--when a millionaire pays."

"The Russian Embassy," said Katherine, frowning. "No, I don't see where that comes in."

"It does not come in directly, Mademoiselle. I went there to get certain information. I saw a particular personage and I threatened him--yes, Mademoiselle, I, Hercule Poirot, threatened him."

"With the police?"

"No," said Poirot drily, "with the Press--a much more deadly weapon."

He looked at Katherine and she smiled at him, just shaking her head.

"Are you not just turning back into an oyster again, Monsieur Poirot?"

"No, no! I do not wish to make mysteries. See, I will tell you everything. I suspect this man of being the active party in the sale of the jewels of Monsieur Van Aldin. I tax him with it, and in the end I get the whole story out of him. I learn where the jewels were handed over, and I learn, too, of the man who paced up and down outside in the street--a man with a venerable head of white hair, but who walked with the light, springy step of a young man--and I give that man a name in my own mind--the name of 'Monsieur le Marquis.'"

"And now you have come to London to see Mr. Van Aldin?"

"Not entirely for that reason. I had other work to do. Since I have been in London I have seen two more people--a theatrical agent and a Harley Street doctor. From each of them I have got certain information. Put these things together, Mademoiselle, and see if you can make of them the same as I do."

"I?"

"Yes, you. I will tell you one thing, Mademoiselle. There has been a doubt all along in my mind as to whether the robbery and the murder were done by the same person. For a long time I was not sure--"

"And now?"

"And now I _know_."

There was a silence. Then Katherine lifted her head. Her eyes were shining.

"I am not clever like you, Monsieur Poirot. Half the things that you have been telling me don't seem to me to point anywhere at all. The ideas that came to me came from such an entirely different angle--"

"Ah, but that is always so," said Poirot quietly. "A mirror shows the truth, but every one stands in a different place for looking into the mirror."

"My ideas may be absurd--they may be entirely different from yours, but--"

"Yes?"

"Tell me, does this help you at all?"

He took a newspaper cutting from her outstretched hand. He read it and, looking up, he nodded gravely.

"As I told you, Mademoiselle, one stands at a different angle for looking into the mirror, but it is the same mirror and the same things are reflected there."

Katherine got up. "I must rush," she said. "I have only just time to catch my train. Monsieur Poirot--"

"Yes, Mademoiselle."

"It--it mustn't be much longer, you understand. I--I can't go on much longer."

There was a break in her voice.

He patted her hand reassuringly.

"Courage, Mademoiselle, you must not fail now; the end is very near."

33. A New Theory

"Monsieur Poirot wants to see you, sir."

"Damn the fellow!" said Van Aldin.

Knighton remained sympathetically silent.

Van Aldin got up from his chair and paced up and down.

"I suppose you have seen the cursed newspapers this morning?"

"I have glanced at them, sir."

"Still at it hammer and tongs?"

"I am afraid so, sir."

The millionaire sat down again and pressed his hand to his forehead.

"If I had had an idea of this," he groaned. "I wish to God I had never got that little Belgian to ferret out the truth. Find Ruth's murderer--that was all I thought about."

"You wouldn't have liked your son-in-law to go scot free?"

Van Aldin sighed.

"I would have preferred to take the law into my own hands."

"I don't think that would have been a very wise proceeding, sir."

"All the same--are you sure the fellow wants to see me?"

"Yes, Mr. Van Aldin. He is very urgent about it."

"Then I suppose he will have to. He can come along this morning if he likes."

It was a very fresh and debonair Poirot who was ushered in. He did not seem to see any lack of cordiality in the millionaire's manner, and chatted pleasantly about various trifles. He was in London, he explained, to see his doctor. He mentioned the name of an eminent surgeon.

"No, no, _pas la guerre_--a memory of my days in the police force, a bullet of a rascally Apache."

He touched his left shoulder and winced realistically.

"I always consider you a lucky man, Monsieur Van Aldin; you are not like our popular idea of American millionaires, martyrs to the dyspepsia."

"I am pretty tough," said Van Aldin. "I lead a very simple life, you know; plain fare and not too much of it."

"You have seen something of Miss Grey, have you not?" inquired Poirot, innocently turning to the secretary.

"I--yes; once or twice," said Knighton.

He blushed slightly and Van Aldin exclaimed in surprise:

"Funny you never mentioned to me that you had seen her, Knighton?"

"I didn't think you would be interested, sir."

"I like that girl very much," said Van Aldin.

"It is a thousand pities that she should have buried herself once more in St. Mary Mead," said Poirot.

"It is very fine of her," said Knighton hotly. "There are very few people who would bury themselves down there to look after a cantankerous old woman who has no earthly claim on her."

"I am silent," said Poirot, his eyes twinkling a little; "but all the same I say it is a pity. And now, Messieurs, let us come to business."

Both the other men looked at him in some surprise.

"You must not be shocked or alarmed at what I am about to say. Supposing, Monsieur Van Aldin, that, after all, Monsieur Derek Kettering did not murder his wife?"

"What?"

Both men stared at him in blank surprise.

"Supposing, I say, that Monsieur Kettering did not murder his wife?"

"Are you mad, Monsieur Poirot?"

It was Van Aldin who spoke.

"No," said Poirot, "I am not mad. I am eccentric, perhaps--at least certain people say so; but as regards my profession, I am very much, as one says, 'all there.' I ask you, Monsieur Van Aldin, whether you would be glad or sorry if what I tell you should be the case?"

Van Aldin stared at him.

"Naturally I should be glad," he said at last. "Is this an exercise in suppositions, Monsieur Poirot, or are there any facts behind it?"

Poirot looked at the ceiling.

"There is an off-chance," he said quietly, "that it might be the Comte de la Roche after all. At least I have succeeded in upsetting his alibi."

"How did you manage that?"

Poirot shrugged his shoulders modestly.

"I have my own methods. The exercise of a little tact, a little cleverness--and the thing is done."

"But the rubies," said Van Aldin, "these rubies that the Count had in his possession were false."

"And clearly he would not have committed the crime except for the rubies. But you are overlooking one point, Monsieur Van Aldin. Where the rubies were concerned, some one might have been before him."

"But this is an entirely new theory," cried Knighton.

"Do you really believe all this rigmarole, Monsieur Poirot?" demanded the millionaire.

"The thing is not proved," said Poirot quietly. "It is as yet only a theory, but I tell you this, Monsieur Van Aldin, the facts are worth investigating. You must come out with me to the south of France and go into the case on the spot."

"You really think this is necessary--that I should go, I mean."

"I thought it would be what you yourself would wish," said Poirot.

There was a hint of reproach in his tone which was not lost upon the other.

"Yes, yes, of course," he said. "When do you wish to start, Monsieur Poirot?"

"You are very busy at present, sir," murmured Knighton.

But the millionaire had now made up his mind, and he waved the other's objections aside.

"I guess this business comes first," he said. "All right, Monsieur Poirot, to-morrow. What train?"

"We will go, I think, by the Blue Train," said Poirot, and he smiled.

34. The Blue Train Again

"The Millionaire's Train," as it is sometimes called, swung round a curve of line at what seemed a dangerous speed. Van Aldin, Knighton, and Poirot sat together in silence. Knighton and Van Aldin had two compartments connecting with each other, as Ruth Kettering and her maid had had on the fateful journey. Poirot's own compartment was further along the coach.

The journey was a painful one for Van Aldin, recalling as it did the most agonizing memories. Poirot and Knighton conversed occasionally in low tones without disturbing him.

When, however, the train had completed its slow journey round the _ceinture_ and reached the Gare de Lyon, Poirot became suddenly galvanized into activity. Van Aldin realized that part of his object in travelling by the train had been to attempt to reconstruct the crime. Poirot himself acted every part. He was in turn the maid, hurriedly shut into her own compartment, Mrs. Kettering, recognizing her husband with surprise and a trace of anxiety, and Derek Kettering discovering that his wife was travelling on the train. He tested various possibilities, such as the best way for a person to conceal himself in the second compartment.

Then suddenly an idea seemed to strike him. He clutched at Van Aldin's arm.

"_Mon Dieu_, but that is something I have not thought of! We must break our journey in Paris. Quick, quick, let us alight at once."

Seizing suit-cases he hurried from the train. Van Aldin and Knighton, bewildered but obedient, followed him. Van Aldin having once formed his opinion of Poirot's ability was slow to part from it. At the barrier they were held up. Their tickets were in charge of the conductor of the train, a fact which all three of them had forgotten.

Poirot's explanations were rapid, fluent, and impassioned, but they produced no effect upon the stolid-faced official.

"Let us get quit of this," said Van Aldin abruptly. "I gather you are in a hurry, Monsieur Poirot. For God's sake pay the fares from Calais and let us get right on with whatever you have got in your mind."

But Poirot's flood of language had suddenly stopped dead, and he had the appearance of a man turned to stone. His arm, still outflung in an impassioned gesture, remained there as though stricken with paralysis.

"I have been an imbecile," he said simply. "_Ma foi_, I lose my head nowadays. Let us return and continue our journey quietly. With reasonable luck the train will not have gone."

They were only just in time, the train moving off as Knighton, the last of the three, swung himself and his suitcase on board.

The conductor remonstrated with them feelingly, and assisted them to carry their luggage back to their compartments. Van Aldin said nothing, but he was clearly disgusted at Poirot's extraordinary conduct. Alone with Knighton for a moment or two, he remarked:

"This is a wildgoose chase. The man has lost his grip on things. He has got brains up to a point, but any man who loses his head and scuttles round like a frightened rabbit is no earthly darned good."

Poirot came to them in a moment or two, full of abject apologies and clearly so crestfallen that harsh words would have been superfluous. Van Aldin received his apologies gravely, but managed to restrain himself from making acid comments.

They had dinner on the train, and afterwards, somewhat to the surprise of the other two, Poirot suggested that they should all three set up in Van Aldin's compartment.

The millionaire looked at him curiously.

"Is there anything that you are keeping back from us, Monsieur Poirot?"

"I?" Poirot opened his eyes in innocent surprise. "But what an idea."

Van Aldin did not answer, but he was not satisfied. The conductor was told that he need not make up the beds. Any surprise he might have felt was obliterated by the largeness of the tip which Van Aldin handed to him. The three men sat in silence. Poirot fidgeted and seemed restless. Presently he turned to the secretary.

"Major Knighton, is the door of your compartment bolted? The door into the corridor, I mean."

"Yes; I bolted it myself just now."

"Are you sure?" said Poirot.

"I will go and make sure, if you like," said Knighton smiling.

"No, no, do not derange yourself. I will see for myself."

He passed through the connecting door and returned in a second or two, nodding his head.

"Yes, yes, it is as you said. You must pardon an old man's fussy ways."

He closed the connecting door and resumed his place in the right-hand corner.

The hours passed. The three men dozed fitfully, waking with uncomfortable starts. Probably never before had three people booked berths on the most luxurious train available, then declined to avail themselves of the accommodations they had paid for. Every now and then Poirot glanced at his watch, and then nodded his head and composed himself to slumber once more. On one occasion he rose from his seat and opened the connecting door, peered sharply into the adjoining compartment, and then returned to his seat, shaking his head.

"What is the matter?" whispered Knighton. "You are expecting something to happen, aren't you?"

"I have the nerves," confessed Poirot. "I am like the cat upon the hot tiles. Every little noise it makes me jump."

Knighton yawned.

"Of all the darned uncomfortable journeys," he murmured. "I suppose you know what you are playing at, Monsieur Poirot."

He composed himself to sleep as best he could. Both he and Van Aldin had succumbed to slumber, when Poirot, glancing for the fourteenth time at his watch, leant across and tapped the millionaire on the shoulder.

"Eh? What is it?"

"In five or ten minutes, Monsieur, we shall arrive at Lyons."

"My God!" Van Aldin's face looked white and haggard in the dim light. "Then it must have been about this time that poor Ruth was killed."

He sat staring straight in front of him. His lips twitched a little, his mind reverting back to the terrible tragedy that had saddened his life.

There was the usual long screaming sigh of the brake, and the train slackened speed and drew into Lyons. Van Aldin let down the window and leant out.

"If it wasn't Derek--if your new theory is correct, it is here that the man left the train?" he asked over his shoulder.

Rather to his surprise Poirot shook his head.

"No," he said thoughtfully, "no _man_ left the train, but I think--yes, I think, a _woman_ may have done so."

Knighton gave a gasp.

"A woman?" demanded Van Aldin sharply.

"Yes, a woman," said Poirot, nodding his head. "You may not remember, Monsieur Van Aldin, but Miss Grey in her evidence mentioned that a youth in a cap and overcoat descended on to the platform ostensibly to stretch his legs. Me, I think that that youth was most probably a woman."

"But who was she?"

Van Aldin's face expressed incredulity, but Poirot replied seriously and categorically.

"Her name--or the name under which she was known, for many years--is Kitty Kidd, but you, Monsieur Van Aldin, knew her by another name--_that of Ada Mason_."

Knighton sprang to his feet.

"What?" he cried.

Poirot swung round to him.

"Ah!--before I forget it." He whipped something from a pocket and held it out.

"Permit me to offer you a cigarette--out of your own cigarette case. It was careless of you to drop it when you boarded the train on the _ceinture_ at Paris."

Knighton stood staring at him as though stupefied. Then he made a movement, but Poirot flung up his hand in a warning gesture.

"No, don't move," he said in a silky voice; "the door into the next compartment is open, and you are being covered from there this minute. I unbolted the door into the corridor when we left Paris, and our friends the police were told to take their places there. As I expect you know, the French police want you rather urgently, Major Knighton--or shall we say--Monsieur le Marquis?"

35. Explanations

"Explanations?"

Poirot smiled. He was sitting opposite the millionaire at a luncheon table in the latter's private suite at the Negresco. Facing him was a relieved but very puzzled man. Poirot leant back in his chair, lit one of his tiny cigarettes, and stared reflectively at the ceiling.

"Yes, I will give you explanations. It began with the one point that puzzled me. You know what that point was? _The disfigured face._ It is not an uncommon thing to find when investigating a crime and it rouses an immediate question, the question of identity. That naturally was the first thing that occurred to me. Was the dead woman really Mrs. Kettering? But that line led me nowhere, for Miss Grey's evidence was positive and very reliable, so I put that idea aside. The dead woman _was_ Ruth Kettering."

"When did you first begin to suspect the maid?"

"Not for some time, but one peculiar little point drew my attention to her. The cigarette case found in the railway carriage and which she told us was one which Mrs. Kettering had given to her husband. Now that was, on the face of it, most improbable, seeing the terms that they were on. It awakened a doubt in my mind as to the general veracity of Ada Mason's statements. There was the rather suspicious fact to be taken into consideration, that she had only been with her mistress for two months. Certainly it did not seem as if she could have had anything to do with the crime since she had been left behind in Paris and Mrs. Kettering had been seen alive by several people afterwards, but--"

Poirot leant forward. He raised an emphatic forefinger and wagged it with intense emphasis at Van Aldin.

"But I am a good detective. I suspect. There is nobody and nothing that I do not suspect. I believe nothing that I am told. I say to myself: how do we know that Ada Mason was left behind in Paris? And at first the answer to that question seemed completely satisfactory. There was the evidence of your secretary, Major Knighton, a complete outsider whose testimony might be supposed to be entirely impartial, and there was the dead woman's own words to the conductor on the train. But I put the latter point aside for the moment, because a very curious idea--an idea perhaps fantastic and impossible--was growing up in my mind. If by any outside chance it happened to be true, that particular piece of testimony was worthless.

"I concentrated on the chief stumbling-block to my theory, Major Knighton's statement that he saw Ada Mason at the Ritz after the Blue Train had left Paris. That seemed conclusive enough, but yet, on examining the facts carefully, I noted two things. First, that by a curious coincidence he, too, had been exactly two months in your service. Secondly, his initial letter was the same--'K.' Supposing--just supposing--that it was _his_ cigarette case which had been found in the carriage. Then, if Ada Mason and he were working together, and she recognized it when we showed it to her, would she not act precisely as she had done? At first, taken aback, she quickly evolved a plausible theory that would agree with Mr. Kettering's guilt. _Bien entendu_, that was not the original idea. The Comte de la Roche was to be the scapegoat, though Ada Mason would not make her recognition of him too certain, in case he should be able to prove an alibi. Now, if you will cast your mind back to that time, you will remember a significant thing that happened. I suggested to Ada Mason that the man she had seen was not the Comte de la Roche, but Derek Kettering. She seemed uncertain at the time, but after I had got back to my hotel you rang me up and told me that she had come to you and said that, on thinking it over, she was now quite convinced that the man in question _was_ Mr. Kettering. I had been expecting something of the kind. There could be but one explanation of this sudden certainty on her part. After my leaving your hotel, she had had time to consult with somebody, and had received instructions which she acted upon. Who had given her these instructions? Major Knighton. And there was another very small point, which might mean nothing or might mean a great deal. In casual conversation Knighton had talked of a jewel robbery in Yorkshire in a house where he was staying. Perhaps a mere coincidence--perhaps another small link in the chain."

"But there is one thing I do not understand, Monsieur Poirot. I guess I must be dense or I would have seen it before now. Who was the man in the train at Paris? Derek Kettering or the Comte de la Roche?"

"That is the simplicity of the whole thing. _There was no man._ Ah--_mille tonnerres!_--do you not see the cleverness of it all? Whose word have we for it that there ever was a man there? Only Ada Mason's. And we believe in Ada Mason because of Knighton's evidence that she was left behind in Paris."

"But Ruth herself told the conductor that she had left her maid behind there," demurred Van Aldin.

"Ah! I am coming to that. We have Mrs. Kettering's own evidence there, but, on the other hand, we have not really got her evidence, because, Monsieur Van Aldin, a dead woman cannot give evidence. It is not _her_ evidence, but the evidence of the conductor of the train--a very different affair altogether."

"So you think the man was lying?"

"No, no, not at all. He spoke what he thought to be the truth. But the woman who told him that she had left her maid in Paris was not Mrs. Kettering."

Van Aldin stared at him.

"Monsieur Van Aldin, Ruth Kettering was dead before the train arrived at the Gare de Lyon. It was Ada Mason, dressed in her mistress's very distinctive clothing, who purchased a dinner basket and who made that very necessary statement to the conductor."

"Impossible!"

"No, no, Monsieur Van Aldin; not impossible. _Les femmes_, they look so much alike nowadays that one identifies them more by their clothing than by their faces. Ada Mason was the same height as your daughter. Dressed in that very sumptuous fur coat and the little red lacquer hat jammed down over her eyes, with just a bunch of auburn curls showing over each ear, it was no wonder that the conductor was deceived. He had not previously spoken to Mrs. Kettering, you remember. True, he had seen the maid just for a moment when she handed him the tickets, but his impression had been merely that of a gaunt, black-clad female. If he had been an unusually intelligent man, he might have gone so far as to say that mistress and maid were not unlike, but it is extremely unlikely that he would even think that. And remember, Ada Mason, or Kitty Kidd, was an actress, able to change her appearance and tone of voice at a moment's notice. No, no; there was no danger of his recognizing the maid in the mistress's clothing, but there _was_ the danger that when he came to discover the body he might realize it was not the woman he had talked to the night before. And now we see the reason for the disfigured face. The chief danger that Ada Mason ran was that Katherine Grey might visit her compartment after the train left Paris, and she provided against that difficulty by ordering a dinner basket and by locking herself in her compartment."

"But who killed Ruth--and when?"

"First, bear it in mind that the crime was planned and undertaken by the two of them--Knighton and Ada Mason, working together. Knighton was in Paris that day on your business. He boarded the train somewhere on its way round the _ceinture_. Mrs. Kettering would be surprised, but she would be quite unsuspicious. Perhaps he draws her attention to something out the window, and as she turns to look he slips the cord round her neck--and the whole thing is over in a second or two. The door of the compartment is locked, and he and Ada Mason set to work. They strip off the dead woman's outer clothes. Mason and Knighton roll the body up in a rug and put it on the seat in the adjoining compartment amongst the bags and suit-cases. Knighton drops off the train, taking the jewel-case containing the rubies with him. Since the crime is not supposed to have been committed until nearly twelve hours later he is perfectly safe, and his evidence and the supposed Mrs. Kettering's words to the conductor will provide a perfect alibi for his accomplice.

"At the Gare de Lyon Ada Mason gets a dinner basket, and shutting herself into the toilet compartment she quickly changes into her mistress's clothes, adjusts two false bunches of auburn curls, and generally makes up to resemble her as closely as possible. When the conductor comes to make up the bed, she tells him the prepared story about having left her maid behind in Paris; and whilst he is making up the berth, she stands looking out of the window, so that her back is towards the corridor and people passing along there. That was a wise precaution, because, as we know, Miss Grey was one of those passing, and she, among others, was willing to swear that Mrs. Kettering was still alive at that hour."

"Go on," said Van Aldin.

"Before getting to Lyons, Ada Mason arranged her mistress's body in the bunk, folded up the dead woman's clothes neatly on the end of it, and herself changed into a man's clothes and prepared to leave the train. When Derek Kettering entered his wife's compartment, and, as he thought, saw her asleep in her berth, the scene had been set, and Ada Mason was hidden in the next compartment waiting for the moment to leave the train unobserved. As soon as the conductor had swung himself down on to the platform at Lyons, she follows, slouching along as though just taking a breath of air. At a moment when she is unobserved, she hurriedly crosses to the other platform, and takes the first train back to Paris and the Ritz Hotel. Her name has been registered there as taking a room the night before by one of Knighton's female accomplices. She has nothing to do but wait there placidly for your arrival. The jewels are not, and never have been, in her possession. No suspicion attaches to him, and, as your secretary, he brings them to Nice without the least fear of discovery. Their delivery there to Monsieur Papopolous is already arranged for and they are entrusted to Mason at the last moment to hand over to the Greek. Altogether a very neatly planned coup, as one would expect from a master of the game such as the Marquis."

"And you honestly mean that Richard Knighton is a well-known criminal, who has been at this business for years?"

Poirot nodded.

"One of the chief assets of the gentleman called the Marquis was his plausible, ingratiating manner. You fell a victim to his charm, Monsieur Van Aldin, when you engaged him as a secretary on such a slight acquaintanceship."

"I could have sworn that he never angled for the post," cried the millionaire.

"It was very astutely done--so astutely done that it deceived a man whose knowledge of other men is as great as yours is."

"I looked up his antecedents too. The fellow's record was excellent."

"Yes, yes; that was part of the game. As Richard Knighton his life was quite free from reproach. He was well born, well connected, did honourable service in the War, and seemed altogether above suspicion; but when I came to glean information about the mysterious Marquis, I found many points of similarity. Knighton spoke French like a Frenchman, he had been in America, France, and England at much the same time as the Marquis was operating. The Marquis was last heard of as engineering various jewel robberies in Switzerland, and it was in Switzerland that you had come across Major Knighton; and it was at precisely that time that the first rumours were going round of your being in treaty for the famous rubies."

"But why murder?" murmured Van Aldin brokenly. "Surely a clever thief could have stolen the jewels without running his head into a noose."

Poirot shook his head. "This is not the first murder that lies to the Marquis's charge. He is a killer by instinct; he believes, too, in leaving no evidence behind him. Dead men and women tell no tales.

"The Marquis had an intense passion for famous and historical jewels. He laid his plans far beforehand by installing himself as your secretary and getting his accomplice to obtain the situation of maid with your daughter, for whom he guessed the jewels were destined. And, though this was his matured and carefully thought-out plan, he did not scruple to attempt a shortcut by hiring a couple of Apaches to waylay you in Paris on the night you bought the jewels. That plan failed, which hardly surprised him, I think. This plan was, so he thought, completely safe. No possible suspicion could attach to Richard Knighton. But like all great men--and the Marquis was a great man--he had his weaknesses. He fell genuinely in love with Miss Grey, and suspecting her liking for Derek Kettering, he could not resist the temptation to saddle him with the crime when the opportunity presented itself. And now, Monsieur Van Aldin, I am going to tell you something very curious. Miss Grey is not a fanciful woman by any means, yet she firmly believes that she felt your daughter's presence beside her one day in the Casino Gardens at Monte Carlo, just after she had been having a long talk with Knighton. She was convinced, she says, that the dead woman was urgently trying to tell her something, and it suddenly came to her that what the dead woman was trying to say was that Knighton was her murderer! The idea seemed so fantastic at the time that Miss Grey spoke of it to no one. But she was so convinced of its truth that she acted on it--wild as it seemed. She did not discourage Knighton's advances, and she pretended to him that she was convinced of Derek Kettering's guilt."

"Extraordinary," said Van Aldin.

"Yes, it is very strange. One cannot explain these things. Oh, by the way, there is one little point that baffled me considerably. Your secretary has a decided limp--the result of a wound that he received in the War. Now the Marquis most decidedly did not limp. That was a stumbling-block. But Miss Lenox Tamplin happened to mention one day that Knighton's limp had been a surprise to the surgeons who had been in charge of the case in her mother's hospital. That suggested camouflage. When I was in London I went to the surgeon in question, and I got several technical details from him which confirmed me in that belief. I mentioned the name of that surgeon in Knighton's hearing the day before yesterday. The natural thing would have been for Knighton to mention that he had been attended by him during the War, but he said nothing--and that little point, if nothing else, gave me the last final assurance that my theory of the crime was correct. Miss Grey, too, provided me with a cutting, showing that there had been a robbery at Lady Tamplin's hospital during the time that Knighton had been there. She realized that I was on the same track as herself when I wrote to her from the Ritz in Paris.

"I had some trouble in my inquiries there, but I got what I wanted--evidence that Ada Mason arrived on the morning after the crime and not on the evening of the day before."

There was a long silence, then the millionaire stretched out a hand to Poirot across the table.

"I guess you know what this means to me, Monsieur Poirot," he said huskily. "I am sending you round a cheque in the morning, but no cheque in the world will express what I feel about what you have done for me. You are the goods, Monsieur Poirot. Every time, you are the goods."

Poirot rose to his feet; his chest swelled.

"I am only Hercule Poirot," he said modestly, "yet, as you say, in my own way I am a big man, even as you also are a big man. I am glad and happy to have been of service to you. Now I go to repair the damages caused by travel. Alas! my excellent Georges is not with me."

In the lounge of the hotel he encountered a friend--the venerable Monsieur Papopolous, his daughter Zia beside him.

"I thought you had left Nice, Monsieur Poirot," murmured the Greek as he took the detective's affectionately proffered hand.

"Business compelled me to return, my dear Monsieur Papopolous."

"Business?"

"Yes, business. And talking of business, I hope your health is better, my dear friend?"

"Much better. In fact, we are returning to Paris to-morrow."

"I am enchanted to hear such good news. You have not completely ruined the Greek ex-Minister, I hope."

"I?"

"I understand you sold him a very wonderful ruby which--strictly _entre nous_--is being worn by Mademoiselle Mirelle, the dancer?"

"Yes," murmured Monsieur Papopolous; "yes, that is so."

"A ruby not unlike the famous 'Heart of Fire'."

"It has points of resemblance, certainly," said the Greek casually.

"You have a wonderful hand with jewels, Monsieur Papopolous. I congratulate you. Mademoiselle Zia, I am desolate that you are returning to Paris so speedily. I had hoped to see some more of you now that my business is accomplished."

"Would one be indiscreet if one asked what that business was?" asked Monsieur Papopolous.

"Not at all, not at all. I have just succeeded in laying the Marquis by the heels."

A far-away look came over Monsieur Papopolous' noble countenance.

"The Marquis?" he murmured; "now why does that seem familiar to me? No--I cannot recall it."

"You would not, I am sure," said Poirot. "I refer to a very notable criminal and jewel robber. He has just been arrested for the murder of the English lady, Madame Kettering."

"Indeed? How interesting these things are!"

A polite exchange of farewells followed, and when Poirot was out of earshot, Monsieur Papopolous turned to his daughter.

"Zia," he said, with feeling, "that man is the devil!"

"I like him."

"I like him myself," admitted Monsieur Papopolous. "But he is the devil, all the same."

36. By the Sea

The mimosa was nearly over. The scent of it in the air was faintly unpleasant. There were pink geraniums twining along the balustrade of Lady Tamplin's villa, and masses of carnations below sent up a sweet, heavy perfume. The Mediterranean was at its bluest. Poirot sat on the terrace with Lenox Tamplin. He had just finished telling her the same story he had told to Van Aldin two days before. Lenox had listened to him with absorbed attention, her brows knitted and her eyes sombre.

When he had finished she said simply:

"And Derek?"

"He was released yesterday."

"And he has gone--where?"

"He left Nice last night."

"For St. Mary Mead?"

"Yes, for St. Mary Mead."

There was a pause.

"I was wrong about Katherine," said Lenox. "I thought she did not care."

"She is very reserved. She trusts no one."

"She might have trusted me," said Lenox, with a shade of bitterness.

"Yes," said Poirot gravely, "she might have trusted you. But Mademoiselle Katherine has spent a great deal of her life listening, and those who have listened do not find it easy to talk; they keep their sorrows and joys to themselves and tell no one."

"I was a fool," said Lenox; "I thought she really cared for Knighton. I ought to have known better. I suppose I thought so because--well, I hoped so."

Poirot took her hand and gave it a little friendly squeeze. "Courage, Mademoiselle," he said gently.

Lenox looked very straight out across the sea, and her face, in its ugly rigidity, had for the moment a tragic beauty.

"Oh, well," she said at last, "it would not have done. I am too young for Derek; he is like a kid that has never grown up. He wants the Madonna touch."

There was a long silence, then Lenox turned to him quickly and impulsively. "But I _did_ help, Monsieur Poirot--at any rate I did help."

"Yes, Mademoiselle. It was you who gave me the first inkling of the truth when you said that the person who committed the crime need not have been on the train at all. Before that, I could not see how the thing had been done."

Lenox drew a deep breath.

"I am glad," she said; "at any rate--that is something."

From far behind them there came a long-drawn-out scream of an engine's whistle.

"That is that damned Blue Train," said Lenox. "Trains are relentless things, aren't they, Monsieur Poirot? People are murdered and die, but they go on just the same. I am talking nonsense, but you know what I mean."

"Yes, yes, I know. Life is like a train, Mademoiselle. It goes on. And it is a good thing that that is so."

"Why?"

"Because the train gets to its journey's end at last, and there is a proverb about that in your language, Mademoiselle."

"'Journeys end in lovers meeting.'" Lenox laughed. "That is not going to be true for me."

"Yes--yes, it is true. You are young, younger than you yourself know. Trust the train, Mademoiselle, for it is _le bon Dieu_ who drives it."

The whistle of the engine came again.

"Trust the train, Mademoiselle," murmured Poirot again. "And trust Hercule Poirot. He knows."