The Mystery of the Blue Train

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 someone?'

“Yes.”

“Someone who knows something?”

“Someone 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 roost 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:

“And the tip I gave you? You have had your little flutter on the horse?”

“I am in communication with – er – my bookmaker,” replied Poirot.

The eyes of the two men met.

“A well-known horse, eh?”

“No,” said Poirot; “it is what our friends, the English, call a dark horse.”

“Ah!” said M. Papopolous thoughtfully.

“Now we must step across to the Casino and have our little flutter at the roulette table,” cried Poirot gaily.

At the Casino the party separated, Poirot devoting himself solely to Zia, whilst Papopolous himself drifted away.

Poirot was not fortunate, but Zia had a run of good luck, and had soon won a few thousand francs.

“It would be as well,” she observed drily to Poirot, “if I stopped now.”

Poirot's eyes twinkled.

“Superb!” he exclaimed. “You are the daughter of your father, Mademoiselle Zia. To know when to stop. Ah! that is the art.”

He looked round the rooms.

“I cannot see your father anywhere about,” he remarked carelessly. “I will fetch your cloak for you. Mademoiselle, and we will go out in the gardens.”

He did not, however, go straight to the cloak-room. His sharp eyes had seen but a little while before the departure of M. Papopolous.

He was anxious to know what had become of the wily Greek. He ran him to earth unexpectedly in the big entrance hall.

He was standing by one of the pillars, talking to a lady who had just arrived. The lady was Mirelle.

Poirot sidled unostentatiously round the room. He arrived at the other side of the pillar, and unnoticed by the two who were talking together in an animated fashion – or rather, that is to say, the dancer was talking, Papopolous contributing an occasional monosyllable and a good many expressive gestures.

“I tell you I must have time,” the dancer was saying, “If you give me time I will get the money.”

“To wait” – the Greek shrugged his shoulders – “it is awkward.”

“Only a very little while,” pleaded the other. “Ah! but you must! A week – ten days – that is all I ask. You can be sure of your affair. The money will be forthcoming.”

Papopolous shifted a little and looked round him uneasily – to find Poirot almost at his elbow with a beaming innocent face.

“Ah! vous voila, M. Papopolous. I have been looking for you. It is permitted that I take Mademoiselle Zia for a little turn in the gardens? Good evening. Mademoiselle.” He bowed very low to Mirelle. “A thousand pardons that I did not see you immediately.”

The dancer accepted his greetings rather impatiently. She was clearly annoyed at the interruption of her tete-a-tete. Poirot was quick to take the hint. Papopolous had already murmured: “Certainly – but certainly,” and Poirot withdrew forthwith.

He fetched Zia's cloak, and together they strolled out into the gardens.

“This is where the suicides take place,” said Zia.

Poirot shrugged his shoulders. “So it is said. Men are foolish, are they not. Mademoiselle? To eat, to drink, to breathe the good air, it is a very pleasant thing. Mademoiselle. One is foolish to leave all that simply because one has no money – or because the heart aches. L'amour, it causes many fatalities, does it not?”

Zia laughed.

“You should not laugh at love. Mademoiselle,” said Poirot, shaking an energetic forefinger at her. “You who are young and beautiful.”

“Hardly that,” said Zia; “you forget that I am thirty-three, M. Poirot. I am frank with you, because it is no good being otherwise. As you told my father, it is exactly seventeen years since you aided us in Paris that time.”

“When I look at you, it seems much less,” said Poirot gallantly. “You were then very much as you are now. Mademoiselle, a little thinner, a little paler, a little more serious. Sixteen years old and fresh from your pension. Not quite the petite pensionnaire, not quite a woman. You were very delicious, very charming. Mademoiselle Zia; others thought so too, without doubt.”

“At sixteen,” said Zia, “one is simple and a little fool.”

“That may be,” said Poirot, “yes, that well may be. At sixteen one is credulous, is one not? One believes what one is told.”

If he saw the quick sideways glance that the girl shot at him, he pretended not to have done so. He continued dreamily: “It was a curious affair that, altogether. Your father, Mademoiselle, has never understood the true inwardness of it.”

“No?”

“When he asked me for details, for explanations, I said to him thus: 'Without scandal, I have got back for you that which was lost. You must ask no questions.' Do you know. Mademoiselle, why I said these things?”

“I have no idea,” said the girl coldly.

“It was because I had a soft spot in my heart for a little pensionnaire, so pale, so thin, so serious.”

“I don't understand what you are talking about,” cried Zia angrily.

“Do you not. Mademoiselle? Have you forgotten Antonio Pirezzio?” He heard the quick intake of her breath – almost a gasp.

“He came to work as an assistant in the shop, but not thus could he have got hold of what he wanted. An