The Mystery Of the blue train

Poirot started to keep his dinner appointment with a margin of three-quarters of an hour to spare. He had an object in this. The car took him, not straight to Monte Carlo, but to Lady Tamplin's house at Cap Martin, where he asked for Miss Grey. The ladies were dressing and Poirot was shown into a small salon to wait, and here, after a lapse of three or four minutes, Lenox Tamplin came to him.

"Katherine is not quite ready yet," she said. "Can I give her a message, or would you rather wait until she comes down?"

Poirot looked at her thoughtfully. He was a minute or two in replying, as though something of great weight hung upon his decision. Apparently the answer to such a simple question mattered.

"No," he said at last, "no, I do not think it is necessary that I should wait to see Mademoiselle Katherine. I think, perhaps, that it is better that I should not. These things are sometimes difficult."

Lenox waited politely, her eyebrows slightly raised.

"I have a piece of news," continued Poirot. "You will, perhaps, tell your friend. M. Kettering was arrested to-night for the murder of his wife."

"You want me to tell Katherine that?" asked Lenox. She breathed rather hard, as though she had been running; her face, Poirot thought, looked white and strained—rather noticeably so.

"If you please, Mademoiselle."

"Why?" said Lenox. "Do you think Katherine will be upset? Do you think she cares?"

"I don't know, Mademoiselle," said Poirot. "See, I admit it frankly. As a rule I know everything, but in this case, I—well, I do not. You, perhaps, know better than I do."

"Yes," said Lenox, "I know—but I am not going to tell you all the same."

She paused for a minute or two, her dark brows drawn together in a frown.

"You believe he did it?" she said abruptly.

Poirot shrugged his shoulders.

"The police say so."

"Ah," said Lenox, "hedging, are you? So there is something to hedge about."

Again she was silent, frowning. Poirot said gently:

"You have known Derek Kettering a long time, have you not?"

"Off and on ever since I was a kid," said Lenox gruffly.

Poirot nodded his head several times without speaking.

With one of her brusque movements Lenox drew forward a chair and sat down on it, her elbows on the table and her face supported by her hands. Sitting thus, she looked directly across the table at Poirot.

"What have they got to go on?" she demanded. "Motive, I suppose. Probably came into money at her death."

"He came into two million."

"And if she had not died he would have been ruined?"

"Yes."

"But there must have been more than that," persisted Lenox. "He travelled by the same train, I know, but—that would not be enough to go on by itself."

"A cigarette case with the letter 'K' on it which did not belong to Mrs. Kettering was found in her carriage, and he was seen by two people entering and leaving the compartment just before the train got into Lyons."

"What two people?"

"Your friend Miss Grey was one of them. The other was Mademoiselle Mirelle, the dancer."

"And he, Derek, what has he got to say about it?" demanded Lenox sharply.

"He denies having entered his wife's compartment at all," said Poirot.

"Fool!" said Lenox crisply, frowning. "Just before Lyons, you say? Does nobody know when—when she died?"

"The doctors' evidence necessarily cannot be very definite," said Poirot; "they are inclined to think that death was unlikely to have occurred after leaving Lyons. And we know this much, that a few moments after leaving Lyons Mrs. Kettering was dead."

"How do you know that?"

Poirot was smiling rather oddly to himself.

"Some one else went into her compartment and found her dead."

"And they did not rouse the train?"

"No."

"Why was that?"

"Doubtless they had their reasons."

Lenox looked at him sharply.

"Do you know the reason?"

"I think so—yes."

Lenox sat still turning things over in her mind. Poirot watched her in silence. At last she looked up. A soft colour had come into her cheeks and her eyes were shining.

"You think some one on the train must have killed her, but that need not be so at all. What is to stop any one swinging themselves on to the train when it stopped at Lyons? They could go straight to her compartment, strangle her, and take the rubies and drop off the train again without any one being the wiser. She may have been actually killed while the train was in Lyons station. Then she would have been alive when Derek went in, and dead when the other person found her."

Poirot leant back in his chair. He drew a deep breath. He looked across at the girl and nodded his head three times, then he heaved a sigh.

"Mademoiselle," he said, "what you have said there is very just—very true. I was struggling in darkness, and you have shown me a light. There was a point that puzzled me and you have made it plain."

He got up.

"And Derek?" said Lenox.

"Who knows?" said Poirot, with a shrug of his shoulders. "But I will tell you this, Mademoiselle. I am not satisfied; no, I, Hercule Poirot, am not yet satisfied. It may be that this very night I shall learn something more. At least, I go to try."

"You are meeting some one?"

"Yes."

"Some one who knows something?"

"Some one who might know something. In these matters one must leave no stone unturned. Au revoir, Mademoiselle."

Lenox accompanied him to the door.

"Have I—helped?" she asked.

Poirot's face softened as he looked up at her standing on the doorstep above him.

"Yes, Mademoiselle, you have helped. If things are very dark, always remember that."

When the car had driven off he relapsed into a frowning absorption, but in his eyes was that faint green light which was always the precursor of the triumph to be.

He was a few minutes late at the rendezvous, and found that M. Papopolous and his daughter had arrived before him. His apologies were abject, and he outdid himself in politeness and small attentions. The Greek was looking particularly benign and noble this evening, a sorrowful patriarch of blameless life. Zia was looking handsome and good humoured. The dinner was a pleasant one. Poirot was his best and most sparkling self. He told anecdotes, he made jokes, he paid graceful compliments to Zia Papopolous, and he told many interesting incidents of his career. The menu was a carefully selected one, and the wine was excellent.

At the close of dinner M. Papopolous inquired politely: