“You rely on the intuition? What the Americans call ‘the hunch’?” asked Dr. Constantine.

“Not at all. I regard the probabilities. Hardman is travelling with a false passport – that will at once make him an object of suspicion. The first thing that the police will do when they do arrive upon the scene is to detain Hardman and cable as to whether his account of himself is true. In the case of many of the passengers, to establish their bona fides will be difficult; in most cases it will probably not be attempted, especially since there seems nothing in the way of suspicion attaching to them. But in Hardman’s case it is simple. Either he is the person he represents himself to be, or he is not. Therefore I say that all will prove to be in order.”

“You acquit him of suspicion?”

“Not at all. You misunderstand me. For all I know, any American detective might have his own private reasons for wishing to murder Ratchett. No, what I am saying is that I think we can accept Hardman’s own account of himself. This story, then, that he tells of Ratchett’s seeking him out and employing him is not unlikely, and is most probably – though not of course certainly – true. If we are going to accept it as true, we must see if there is any confirmation of it. We find it in rather an unlikely place – in the evidence of Hildegarde Schmidt. Her description of the man she saw in Wagon Lit uniform tallies exactly. Is there any further confirmation of these two stories? There is. There is the button that Mrs. Hubbard found in her compartment. And there is also another corroborating statement which you may not have noticed.”

“What is that?”

“The fact that both Colonel Arbuthnot and Hector MacQueen mention that the conductor passed their carriage. They attached no importance to the fact, but, Messieurs, Pierre Michel has declared that he did not leave his seat except on certain specified occasions – none of which would take him down to the far end of the coach past the compartment in which Arbuthnot and MacQueen were sitting.

“Therefore this story, the story of a small dark man with a womanish voice dressed in Wagon Lit uniform, rests on the testimony, direct or indirect, of four witnesses.”

“One small point,” said Dr. Constantine. “If Hildegarde Schmidt’s story is true, how is it that the real conductor did not mention having seen her when he came to answer Mrs. Hubbard’s bell?”

“That is explained, I think. When he arrived to answer Mrs. Hubbard, the maid was in with her mistress. When she finally returned to her own compartment, the conductor was in with Mrs. Hubbard.”

M. Bouc had been waiting with difficulty until they had finished.

“Yes, yes, my friend,” he said impatiently to Poirot. “But whilst I admire your caution, your method of advancing a step at a time, I submit that you have not yet touched the point at issue. We are all agreed that this person exists. The point is, where did he go?”

Poirot shook his head reprovingly.

“You are in error. You are inclined to put the cart before the horse. Before I ask myself, ‘Where did this man vanish to?’ I ask myself, ‘Did such a man really exist?’ Because, you see, if the man were an invention – a fabrication – how much easier to make him disappear! So I try to establish first that there really is such a flesh-and-blood person.”

“And having arrived at the fact that there is – eh bien, where is he now?”

“There are only two answers to that, mon cher. Either he is still hidden on the train in a place of such extraordinary ingenuity that we cannot even think of it; or else he is, as one might say, two persons. That is, he is both himself – the man feared by M. Ratchett – and a passenger on the train so well disguised that M. Ratchett did not recognise him.”

“It is an idea, that,” said M. Bouc, his face lighting up. Then it clouded over again. “But there is one objection–”

Poirot took the words out of his mouth.

“The height of the man. It is that you would say? With the exception of Mr. Ratchett’s valet, all the passengers are big men – the Italian, Colonel Arbuthnot, Hector MacQueen, Count Andrenyi. Well, that leaves us the valet – not a very likely supposition. But there is another possibility. Remember the ‘womanish’ voice. That gives us a choice of alternatives. The man may be disguised as a woman, or, alternatively, he may actually be a woman. A tall woman dressed in men’s clothes would look small.”

“But surely Ratchett would have known–”

“Perhaps he did know. Perhaps, already, this woman had attempted his life, wearing a mares clothes the better to accomplish her purpose. Ratchett may have guessed that she would use the same trick again, so he tells Hardman to look for a man. But he mentions, however, a womanish voice.”

“It is a possibility,” said M. Bouc. “But–”

“Listen, my friend, I think that I should now tell you of certain inconsistencies noticed by Dr. Constantine.”

He retailed at length the conclusions that he and the doctor had arrived at together from the nature of the dead man’s wounds. M. Bouc groaned and held his head again. “I know,” said Poirot sympathetically. “I know exactly how you feel. The head spins, does it not?”

“The whole thing is a fantasy!” cried M. Bouc.

“Exactly. It is absurd – improbable – it cannot be. So I myself have said. And yet, my friend, there it is! One cannot escape from the facts.”

“It is madness!”

“Is it not? It is so mad, my friend, that sometimes I am haunted by the sensation that really it must be very simple… But that is only one of my ‘little ideas’!”

“Two murderers,” groaned M. Bouc. “And on the Orient Express–”

The thought almost made him weep.

“And now let us make the fantasy more fantastic,” said Poirot cheerfully. “Last night on the train, there are two mysterious strangers. There is the Wagon Lit attendant answering to the description given us by M. Hardman, and seen by Hildegarde Schmidt, Colonel Arbuthnot and M. MacQueen. There is also a woman in a red kimono – a tall slim woman, seen by Pierre Michel, Miss Debenham, M. MacQueen and myself (and smelt, I may say, by Colonel Arbuthnot!). Who was she? No one on the train admits to having a scarlet kimono. She, too, has vanished. Was she one and the same with the spurious Wagon Lit attendant? Or was she some quite distinct personality? Where are they, these two? And incidentally, where are the Wagon Lit uniform and the scarlet kimono?”

“Ah! that is something definite.” M. Bouc sprang up eagerly. “We must search all the passengers’ luggage. Yes, that will be something.”

Poirot rose also. “I will make a prophecy,” he said.

“You know where they are?”

“I have a little idea.”

“Where, then?”

“You will find the scarlet kimono in the baggage of one of the men, and you will find the uniform of the Wagon Lit conductor in the baggage of Hildegarde Schmidt.”

“Hildegarde Schmidt? You think–”

“Not what you are thinking. I will put it like this. If Hildegarde Schmidt is guilty, the uniform may be found in her baggage. But if she is innocent, it certainly will be.”

“But how–” began M. Bouc and stopped. “What is this noise that approaches?” he cried. “It resembles a locomotive in motion.”

The noise drew nearer. It consisted of shrill cries and protests in a woman’s voice. The door at the end of the dining-car burst open. Mrs. Hubbard burst in.

“It’s too horrible!” she cried. It’s just too horrible. In my sponge-bag. My sponge-bag! A great knife – all over blood?”

And suddenly toppling forward, she fainted heavily on M. Bouc’s shoulder.