1M. Papopolous was at breakfast. Opposite him sat his daughter, Zia.

2There was a knock at the sitting-room door, and a chasseur entered with a card which he brought to Mr. Papopolous. The latter scrutinized it, raised his eyebrows, and passed it over to his daughter.

3"Ah!" said M. Papopolous, scratching his left ear thoughtfully, "Hercule Poirot. I wonder now."

4Father and daughter looked at each other.

5"I saw him yesterday at the tennis," said M. Papopolous. "Zia, I hardly like this."

6"He was very useful to you once," his daughter reminded him.

7"That is true," acknowledged M. Papopolous; "also he has retired from active work, so I hear."

8These interchanges between father and daughter had passed in their own language. Now M. Papopolous turned to the chasseur and said in French:

9"Faites monter ce monsieur."

10A few minutes later Hercule Poirot, exquisitely attired, and swinging a cane with a jaunty air, entered the room.

11"My dear M. Papopolous."

12"My dear M. Poirot."

13"And Mademoiselle Zia." Poirot swept her a low bow.

14"You will excuse us going on with our breakfast," said M. Papopolous, pouring himself out another cup of coffee. "Your call is—ahem!—a little early."

15"It is scandalous," said Poirot, "but see you, I am pressed."

16"Ah!" murmured M. Papopolous, "you are on an affair then?"

17"A very serious affair," said Poirot: "the death of Madame Kettering."

18"Let me see," M. Papopolous looked innocently up at the ceiling, "that was the lady who died on the Blue Train, was it not? I saw a mention of it in the papers, but there was no suggestion of foul play."

19"In the interests of justice," said Poirot, "it was thought best to suppress that fact."

20There was a pause.

21"And in what way can I assist you, M. Poirot?" asked the dealer politely.

22"Voilà," said Poirot, "I shall come to the point." He took from his pocket the same box that he had displayed at Cannes, and opening it, he took out the rubies and pushed them across the table to Papopolous.

23Although Poirot was watching him narrowly, not a muscle of the old man's face moved. He took up the jewels and examined them with a kind of detached interest, then he looked across at the detective inquiringly:

24"Superb, are they not?" asked Poirot.

25"Quite excellent," said M. Papopolous.

26"How much should you say they are worth?"

27The Greek's face quivered a little.

28"Is it really necessary to tell you, M. Poirot?" he asked.

29"You are shrewd, M. Papopolous. No, it is not. They are not, for instance, worth five hundred thousand dollars."

30Papopolous laughed, and Poirot joined with him.

31"As an imitation," said Papopolous, handing them back to Poirot, "they are, as I said, quite excellent. Would it be indiscreet to ask, M. Poirot, where you came across them?"

32"Not at all," said Poirot; "I have no objection to telling an old friend like yourself. They were in the possession of the Comte de la Roche."

33M. Papopolous' eyebrows lifted themselves eloquently.

34"In-deed," he murmured.

35Poirot leant forward and assumed his most innocent and beguiling air.

36"M. Papopolous," he said, "I am going to lay my cards upon the table. The original of these jewels was stolen from Madame Kettering on the Blue Train. Now I will say to you first this: I am not concerned with the recovery of these jewels. That is the affair of the police. I am working not for the police but for M. Van Aldin. I want to lay hands on the man who killed Madame Kettering. I am interested in the jewels only in so far as they may lead me to the man. You understand?"

37The last two words were uttered with great significance. M. Papopolous, his face quite unmoved, said quietly:

38"Go on."

39"It seems to me probable, Monsieur, that the jewels will change hands in Nice—may already have done so."

40"Ah!" said M. Papopolous.

41He sipped his coffee reflectively, and looked a shade more noble and patriarchal than usual.

42"I say to myself," continued Poirot, with animation, "what good fortune! My old friend, M. Papopolous, is in Nice. He will aid me."

43"And how do you think I can aid you?" inquired M. Papopolous coldly.

44"I said to myself, without doubt M. Papopolous is in Nice on business."

45"Not at all," said M. Papopolous, "I am here for my health—by the doctor's orders."

46He coughed hollowly.

47"I am desolated to hear it," replied Poirot, with somewhat insincere sympathy. "But to continue. When a Russian Grand Duke, an Austrian Archduchess, or an Italian Prince wish to dispose of their family jewels—to whom do they go? To M. Papopolous, is it not? He who is famous all over the world for the discretion with which he arranges these things."

48The other bowed.

49"You flatter me."

50"It is a great thing, discretion," mused Poirot, and was rewarded by the fleeting smile which passed across the Greek's face. "I, too, can be discreet."

51The eyes of the two men met.

52Then Poirot went on speaking very slowly, and obviously picking his words with care.

53"I say to myself, this: if these jewels have changed hands in Nice, M. Papopolous would have heard of it. He has knowledge of all that passes in the jewel world."

54"Ah!" said M. Papopolous, and helped himself to a croissant.

55"The police, you understand," said M. Poirot, "do not enter into the matter. It is a personal affair."

56"One hears rumours," admitted M. Papopolous cautiously.

57"Such as?" prompted Poirot.

58"Is there any reason why I should pass them on?"

59"Yes," said Poirot, "I think there is. You may remember, M. Papopolous, that seventeen years ago there was a certain article in your hands, left there as security by a very—er—Prominent Person. It was in your keeping and it unaccountably disappeared. You were, if I may use the English expression, in the soup."

60His eyes came gently round to the girl. She had pushed her cup and plate aside, and with both elbows on the table and her chin resting on her hands was listening eagerly. Still keeping an eye on her he went on:

61"I am in Paris at the time. You send for me. You place yourself in my hands. If I restore to you that—article, you say I shall earn your undying gratitude. Eh bien! I did restore it to you."

62A long sigh came from M. Papopolous.

63"It was the most unpleasant moment of my career," he murmured.

64"Seventeen years is a long time," said Poirot thoughtfully, "but I believe that I am right in saying, Monsieur, that your race does not forget."

65"A Greek?" murmured Papopolous, with an ironical smile.

66"It was not as a Greek I meant," said Poirot.

67There was a silence, and then the old man drew himself up proudly.

68"You are right, M. Poirot," he said quietly. "I am a Jew. And, as you say, our race does not forget."

69"You will aid me then?"

70"As regards the jewels, Monsieur, I can do nothing."

71The old man, as Poirot had done just now, picked his words carefully.

72"I know nothing. I have heard nothing. But I can perhaps do you a good turn—that is, if you are interested in racing."

73"Under certain circumstances I might be," said Poirot, eyeing him steadily.

74"There is a horse running at Longchamps that would, I think, repay attention. I cannot say for certain, you understand; this news passed through so many hands."

75He stopped, fixing Poirot with his eye, as though to make sure that the latter was comprehending him.

76"Perfectly, perfectly," said Poirot, nodding.

77"The name of the horse," said M. Papopolous, leaning back and joining the tips of his fingers together, "is the Marquis. I think, but I am not sure, that it is an English horse, eh, Zia?"

78"I think so too," said the girl.

79Poirot got up briskly.

80"I thank you, Monsieur," he said. "It is a great thing to have what the English call a tip from the stable. Au revoir, Monsieur, and many thanks."

81He turned to the girl.

82"Au revoir, Mademoiselle Zia. It seems to me but yesterday that I saw you in Paris. One would say that two years had passed at most."

83"There is a difference between sixteen and thirty-three," said Zia ruefully.

84"Not in your case," declared Poirot gallantly. "You and your father will perhaps dine with me one night."

85"We shall be delighted," replied Zia.

86"Then we will arrange it," declared Poirot, "and now—je me sauve."

87Poirot walked along the street humming a little tune to himself. He twirled his stick with a jaunty air, once or twice he smiled to himself quietly. He turned into the first Bureau de Poste he came to and sent off a telegram. He took some time in wording it, but it was in code and he had to call upon his memory. It purported to deal with a missing scarf-pin, and was addressed to Inspector Japp, Scotland Yard.

88Decoded, it was short and to the point. "Wire me everything known about man whose soubriquet is the Marquis."