It was five o'clock on a winter's morning in Syria. Alongside the platform at Aleppo stood the train grandly designated in railway guides as the Taurus Express. It consisted of a kitchen and dining car, a sleeping car and two local coaches.

By the step leading up into the sleeping car stood a young French lieutenant, resplendent in uniform, conversing with a small lean man, muffled up to the ears, of whom nothing was visible but a pink-tipped nose and the two points of an upward curled moustache.

It was freezingly cold, and this job of seeing off a distinguished stranger was not one to be envied, but Lieutenant Dubosc performed his part manfully. Graceful phrases fell from his lips in polished French. Not that he knew what it was all about. There had been rumours, of course, as there always were in such cases. The General -- his General's -- temper had grown worse and worse. And then there had come this Belgian stranger -- all the way from England, it seemed. There had been a week -- a week of curious tensity. And then certain things had happened. A very distinguished officer had committed suicide, another had resigned -- anxious faces had suddenly lost their anxiety, certain military precautions were relaxed. And the General -- Lieutenant Dubosc's own particular General -- had suddenly looked ten years younger.

Dubosc had overheard part of a conversation between him and the stranger. "You have saved us, mon cher," said the General emotionally, his great white moustache trembling as he spoke. "You have saved the honour of the French Army -- you have averted much bloodshed! How can I thank you for acceding to my request? To have come so far --"

To which the stranger (by name M. Hercule Poirot) had made a fitting reply including the phrase, "But indeed do I not remember that once you saved my life?" And then the General had made another fitting reply to that disclaiming any merit for that past service, and with more mention of France, of Belgium, of glory, of honour and of such kindred things they had embraced each other heartily and the conversation had ended.

As to what it had all been about, Lieutenant Dubosc was still in the dark, but to him had been delegated the duty of seeing off M. Poirot by the Taurus Express, and he was carrying it out with all the zeal and ardour befitting a young officer with a promising career ahead of him.

"Today is Sunday," said Lieutenant Dubosc. "Tomorrow, Monday evening, you will be in Stamboul."

It was not the first time he had made this observation. Conversations on the platform, before the departure of a train, are apt to be somewhat repetitive in character.

"That is so," agreed M. Poirot.

"And you intend to remain there a few days, I think?"

"Mais oui. Stamboul, it is a city I have never visited. It would be a pity to pass through -- comme ça." He snapped his fingers descriptively. "Nothing presses -- I shall remain there as a tourist for a few days."

"La Sainte Sophie, it is very fine," said Lieutenant Dubosc, who had never seen it.

A cold wind came whistling down the platform. Both men shivered. Lieutenant Dubosc managed to cast a surreptitious glance at his watch. Five minutes to five -- only five minutes more!

Fancying that the other man had noticed his surreptitious glance, he hastened once more into speech.

"There are few people travelling this time of year," he said, glancing up at the windows of the sleeping car above them.

"That is so," agreed M. Poirot.

"Let us hope you will not be snowed up in the Taurus!"

"That happens?"

"It has occurred, yes. Not this year, as yet."

"Let us hope, then," said M. Poirot. "The weather reports from Europe, they are bad."

"Very bad. In the Balkans there is much snow."

"In Germany too, I have heard."

"Eh bien," said Lieutenant Dubosc hastily as another pause seemed to be about to occur. "Tomorrow evening at seven-forty you will be in Constantinople."

"Yes," said M. Poirot, and went on desperately, "La Sainte Sophie, I have heard it is very fine."

"Magnificent, I believe."

Above their heads the blind of one of the sleeping car compartments was pushed aside and a young woman looked out.

Mary Debenham had had little sleep since she left Baghdad on the preceding Thursday. Neither in the train to Kirkuk, nor in the Rest House at Mosul, nor last night on the train had she slept properly. Now, weary of lying wakeful in the hot stuffiness of her overheated compartment, she got up and peered out.

This must be Aleppo. Nothing to see, of course. Just a long, poor-lighted platform with loud furious altercations in Arabic going on somewhere. Two men below her window were talking French. One was a French officer, the other was a little man with enormous moustaches. She smiled faintly. She had never seen anyone quite so heavily muffled up. It must be very cold outside. That was why they heated the train so terribly. She tried to force the window down lower, but it would not go.

The Wagon Lit conductor had come up to the two men. The train was about to depart, he said. Monsieur had better mount. The little man removed his hat. What an egg-shaped head he had. In spite of her preoccupations Mary Debenham smiled. A ridiculous-looking little man. The sort of little man one could never take seriously.

Lieutenant Dubosc was saying his parting speech. He had thought it out beforehand and had kept it till the last minute. It was a very beautiful, polished speech.

Not to be outdone, M. Poirot replied in kind.

"En voiture, Monsieur," said the Wagon Lit conductor.

With an air of infinite reluctance M. Poirot climbed aboard the train. The conductor climbed after him. M. Poirot waved his hand. Lieutenant Dubosc came to the salute. The train, with a terrific jerk, moved slowly forward.

"Enfin!" murmured M. Hercule Poirot.

"Brrrrr," said Lieutenant Dubosc, realizing to the full how cold he was…

"Voilà, Monsieur." The conductor displayed to Poirot with a dramatic gesture the beauty of his sleeping compartment and the neat arrangement of his luggage. "The little valise of Monsieur, I have placed it here."

His outstretched hand was suggestive. Hercule Poirot placed in it a folded note.

"Merci, Monsieur." The conductor became brisk and businesslike. "I have the tickets of Monsieur. I will also take the passport, please. Monsieur breaks his journey in Stamboul, I understand?"

M. Poirot assented. "There are not many people travelling, I imagine?" he said.

"No, Monsieur. I have only two other passengers -- both English. A Colonel from India, and a young English lady from Baghdad. Monsieur requires anything?"

Monsieur demanded a small bottle of Perrier.

Five o'clock in the morning is an awkward time to board a train. There was still two hours before dawn. Conscious of an inadequate night's sleep, and of a delicate mission successfully accomplished, M. Poirot curled up in a corner and fell asleep.

When he awoke it was half-past nine, and he sallied forth to the restaurant car in search of hot coffee.

There was only one occupant at the moment, obviously the young English lady referred to by the conductor. She was tall, slim and dark -- perhaps twenty-eight years of age. There was a kind of cool efficiency in the way she was eating her breakfast and in the way she called to the attendant to bring her more coffee, which bespoke a knowledge of the world and of travelling. She wore a dark-coloured travelling dress of some thin material eminently suitable for the heated atmosphere of the train.

M. Hercule Poirot, having nothing better to do, amused himself by studying her without appearing to do so.

She was, he judged, the kind of young woman who could take care of herself with perfect ease wherever she went. She had poise and efficiency. He rather liked the severe regularity of her features and the delicate pallor of her skin. He liked the burnished black head with its neat waves of hair, and her eyes, cool, impersonal and grey. But she was, he decided, just a little too efficient to be what he called "jolie femme."

Presently another person entered the restaurant car. This was a tall man of between forty and fifty, lean of figure, brown of skin, with hair slightly grizzled round the temples.

"The colonel from India," said Poirot to himself.

The newcomer gave a little bow to the girl.

"Morning, Miss Debenham."

"Good morning, Colonel Arbuthnot."

The Colonel was standing with a hand on the chair opposite her.

"Any objection?" he asked.

"Of course not. Sit down."

"Well, you know, breakfast isn't always a chatty meal."

"I should hope not. But I don't bite."

The Colonel sat down.

"Boy," he called in peremptory fashion.

He gave an order for eggs and coffee.

His eyes rested for a moment on Hercule Poirot, but they passed on indifferently. Poirot, reading the English mind correctly, knew that he had said to himself, "Only some damned foreigner."

True to their nationality, the two English people were not chatty. They exchanged a few brief remarks, and presently the girl rose and went back to her compartment.

At lunch time the other two again shared a table and again they both completely ignored the third passenger. Their conversation was more animated than at breakfast. Colonel Arbuthnot talked of the Punjab, and occasionally asked the girl a few questions about Baghdad where it became clear that she had been in a post as governess. In the course of conversation they discovered some mutual friends which had the immediate effect of making them more friendly and less stiff. They discussed old Tommy Somebody and Jerry Someone Else. The Colonel inquired whether she was going straight through to England or whether she was stopping in Stamboul.

"No, I'm going straight on."

"Isn't that rather a pity?"

"I came out this way two years ago and spent three days in Stamboul then."

"Oh, I see. Well, I may say I'm very glad you are going right through, because I am."

He made a kind of clumsy little bow, flushing a little as he did so.

"He is susceptible, our Colonel," thought Hercule Poirot to himself with some amusement. "The train, it is as dangerous as a sea voyage!"

Miss Debenham said evenly that that would be very nice. Her manner was slightly repressive.

The Colonel, Hercule Poirot noticed, accompanied her back to her compartment. Later they passed through the magnificent scenery of the Taurus. As they looked down towards the Cilician Gates, standing in the corridor side by side, a sigh came suddenly from the girl. Poirot was standing near them and heard her murmur:

"It's so beautiful! I wish -- I wish --"

"Yes?"

"I wish, I could enjoy it!"

Arbuthnot did not answer. The square line of his jaw seemed a little sterner and grimmer.

"I wish to Heaven you were out of all this," he said.

"Hush, please. Hush."

"Oh! it's all right." He shot a slightly annoyed glance in Poirot's direction. Then he went on: "But I don't like the idea of your being a governess -- at the beck and call of tyrannical mothers and their tiresome brats."

She laughed with just a hint of uncontrol in the sound.

"Oh! you mustn't think that. The downtrodden governess is quite an exploded myth. I can assure you that it's the parents who are afraid of being bullied by me."

They said no more. Arbuthnot was, perhaps, ashamed of his outburst.

"Rather an odd little comedy that I watch here," said Poirot to himself thoughtfully.

He was to remember that thought of his later.

They arrived at Konya that night about half-past eleven. The two English travellers got out to stretch their legs, pacing up and down the snowy platform.

M. Poirot was content to watch the teeming activity of the station through a window pane. After about ten minutes, however, he decided that a breath of air would not perhaps be a bad thing, after all. He made careful preparations, wrapping himself in several coats and mufflers and encasing his neat boots in goloshes. Thus attired he descended gingerly to the platform and began to pace its length. He walked out beyond the engine.

It was the voices which gave him the clue to the two indistinct figures standing in the shadow of a traffic van. Arbuthnot was speaking.

"Mary --"

The girl interrupted him.

"Not now. Not now. When it's all over. When it's behind us -- then --"

Discreetly M. Poirot turned away. He wondered.

He would hardly have recognized the cool, efficient voice of Miss Debenham…

"Curious," he said to himself.

The next day he wondered whether, perhaps, they had quarrelled. They spoke little to each other. The girl, he thought, looked anxious. There were dark circles under her eyes.

It was about half-past two in the afternoon when the train came to a halt. Heads were poked out of windows. A little knot of men were clustered by the side of the line looking and pointing at something under the dining car.

Poirot leaned out and spoke to the Wagon Lit conductor who was hurrying past. The man answered and Poirot drew back his head and, turning, almost collided with Mary Debenham who was standing just behind him.

"What is the matter?" she asked rather breathlessly in French. "Why are we stopping?"

"It is nothing, Mademoiselle. It is something that has caught fire under the dining car. Nothing serious. It is put out. They are now repairing the damage. There is no danger, I assure you."

She made a little abrupt gesture, as though she were waving the idea of danger aside as something completely unimportant.

"Yes, yes, I understand that. But the time!"

"The time?"

"Yes, this will delay us."

"It is possible -- yes," agreed Poirot.

"But we can't afford delay! The train is due in at 6:55 and one has to cross the Bosphorus and catch the Simplon Orient Express the other side at nine o'clock. If there is an hour or two of delay we shall miss the connection."

"It is possible, yes," he admitted.

He looked at her curiously. The hand that held the window bar was not quite steady, her lips too were trembling.

"Does it matter to you very much, Mademoiselle?" he asked.

"Yes. Yes, it does. I -- I must catch that train."

She turned away from him and went down the corridor to join Colonel Arbuthnot.

Her anxiety, however, was needless. Ten minutes later the train started again. It arrived at Haydapassar only five minutes late, having made up time on the journey.

The Bosphorus was rough and M. Poirot did not enjoy the crossing. He was separated from his travelling companions on the boat, and did not see them again.

On arrival at the Galata Bridge he drove straight to the Tokatlian Hotel.