1It took the millionaire some few minutes to take the thing in. He stared at Poirot as though dumbfounded. The little Belgian nodded at him gently.

2"Yes," he said, "it alters the position, does it not?"

3"Imitation!"

4He leaned forward.

5"All along, M. Poirot, you have had this idea? All along this is what you have been driving at? You never believed that the Comte de la Roche was the murderer?"

6"I have had doubts," said Poirot quietly. "I said as much to you. Robbery with violence and murder"—he shook his head energetically—"no, it is difficult to picture. It does not harmonize with the personality of the Comte de la Roche."

7"But you believe that he meant to steal the rubies?"

8"Certainly. There is no doubt as to that. See, I will recount to you the affair as I see it. The Comte knew of the rubies and he laid his plans accordingly. He made up a romantic story of a book he was writing, so as to induce your daughter to bring them with her. He provided himself with an exact duplicate. It is clear, is it not, that substitution is what he was after. Madame, your daughter, was not an expert on jewels. It would probably be a long time before she discovered what had occurred. When she did so—well—I do not think she would prosecute the Comte. Too much would come out. He would have in his possession various letters of hers. Oh yes, a very safe scheme from the Comte's point of view—one that he has probably carried out before."

9"It seems clear enough, yes," said Van Aldin musingly.

10"It accords with the personality of the Comte de la Roche," said Poirot.

11"Yes, but now—" Van Aldin looked searchingly at the other. "What actually happened? Tell me that, M. Poirot."

12Poirot shrugged his shoulders.

13"It is quite simple," he said; "some one stepped in ahead of the Comte."

14There was a long pause.

15Van Aldin seemed to be turning things over in his mind. When he spoke it was without beating about the bush.

16"How long have you suspected my son-in-law, M. Poirot?"

17"From the very first. He had the motive and the opportunity. Every one took for granted that the man in Madame's compartment in Paris was the Comte de la Roche. I thought so, too. Then you happened to mention that you had once mistaken the Comte for your son-in-law. That told me that they were of the same height and build, and alike in colouring. It put some curious ideas in my head. The maid had only been with your daughter a short time. It was unlikely that she would know Mr. Kettering well by sight, since he had not been living in Curzon Street; also the man was careful to keep his face turned away."

18"You believe he—murdered her," said Van Aldin hoarsely.

19Poirot raised a hand quickly.

20"No, no, I did not say that—but it is a possibility—a very strong possibility. He was in a tight corner, a very tight corner, threatened with ruin. This was the one way out."

21"But why take the jewels?"

22"To make the crime appear an ordinary one committed by train robbers. Otherwise suspicion might have fallen on him straight away."

23"If that is so, what has he done with the rubies?"

24"That remains to be seen. There are several possibilities. There is a man in Nice who may be able to help, the man I pointed out at the tennis."

25He rose to his feet and Van Aldin rose also and laid his hand on the little man's shoulder. His voice when he spoke was harsh with emotion.

26"Find Ruth's murderer for me," he said, "that is all I ask."

27Poirot drew himself up.

28"Leave it in the hands of Hercule Poirot," he said superbly; "have no fears. I will discover the truth."

29He brushed a speck of fluff from his hat, smiled reassuringly at the millionaire, and left the room. Nevertheless, as he went down the stairs some of the confidence faded from his face.

30"It is all very well," he murmured to himself, "but there are difficulties. Yes, there are great difficulties." As he was passing out of the hotel he came to a sudden halt. A car had drawn up in front of the door. In it was Katherine Grey, and Derek Kettering was standing beside it talking to her earnestly. A minute or two later the car drove off and Derek remained standing on the pavement looking after it. The expression on his face was an odd one. He gave a sudden impatient gesture of the shoulders, sighed deeply, and turned to find Hercule Poirot standing at his elbow. In spite of himself he started. The two men looked at each other. Poirot steadily and unwaveringly and Derek with a kind of light-hearted defiance. There was a sneer behind the easy mockery of his tone when he spoke, raising his eyebrows slightly as he did so.

31"Rather a dear, isn't she?" he asked easily.

32His manner was perfectly natural.

33"Yes," said Poirot thoughtfully, "that describes Mademoiselle Katherine very well. It is very English, that phrase there, and Mademoiselle Katherine, she also is very English."

34Derek remained perfectly still without answering.

35"And yet she is sympathique, is it not so?"

36"Yes," said Derek; "there are not many like her."

37He spoke softly, almost as though to himself. Poirot nodded significantly. Then he leant towards the other and spoke in a different tone, a quiet, grave tone that was new to Derek Kettering.

38"You will pardon an old man, Monsieur, if he says to you something that you may consider impertinent. There is one of your English proverbs that I would quote to you. It says that 'it is well to be off with the old love, before being on with the new.'"

39Kettering turned on him angrily.

40"What the devil do you mean?"

41"You enrage yourself at me," said Poirot placidly. "I expected as much. As to what I mean—I mean, Monsieur, that there is a second car with a lady in it. If you turn your head you will see her."

42Derek spun round. His face darkened with anger.

43"Mirelle, damn her!" he muttered. "I will soon—"

44Poirot arrested the movement he was about to make.

45"Is it wise what you are about to do there?" he asked warningly. His eyes shone softly with a green light in them. But Derek was past noticing the warning signs. In his anger he was completely off his guard.

46"I have broken with her utterly, and she knows it," cried Derek angrily.

47"You have broken with her, yes, but has she broken with you?"

48Derek gave a sudden harsh laugh.

49"She won't break with two million pounds if she can help it," he murmured brutally; "trust Mirelle for that."

50Poirot raised his eyebrows.

51"You have the outlook cynical," he murmured.

52"Have I?" There was no mirth in his sudden wide smile. "I have lived in the world long enough, M. Poirot, to know that all women are pretty much alike." His face softened suddenly. "All save one."

53He met Poirot's gaze defiantly. A look of alertness crept into his eyes, then faded again. "That one," he said, and jerked his head in the direction of Cap Martin.

54"Ah!" said Poirot.

55This quiescence was well calculated to provoke the impetuous temperament of the other.

56"I know what you are going to say," said Derek rapidly, "the kind of life I have led, the fact that I am not worthy of her. You will say that I have no right to think even of such a thing. You will say that it is not a case of giving a dog a bad name—I know that it is not decent to be speaking like this with my wife dead only a few days, and murdered at that."

57He paused for breath, and Poirot took advantage of the pause to remark in his plaintive tone:

58"But, indeed, I have not said anything at all."

59"But you will."

60"Eh?" said Poirot.

61"You will say that I have no earthly chance of marrying Katherine."

62"No," said Poirot, "I would not say that. Your reputation is bad, yes, but with women—never does that deter them. If you were a man of excellent character, of strict morality who had done nothing that he should not do, and—possibly everything that he should do—eh bien! then I should have grave doubts of your success. Moral worth, you understand, it is not romantic. It is appreciated, however, by widows."

63Derek Kettering stared at him, then he swung round on his heel and went up to the waiting car.

64Poirot looked after him with some interest. He saw the lovely vision lean out of the car and speak.

65Derek Kettering did not stop. He lifted his hat and passed straight on.

66"Ça y est," said M. Hercule Poirot, "it is time, I think, that I return chez moi."

67He found the imperturbable George pressing trousers.

68"A pleasant day, Georges, somewhat fatiguing, but not without interest," he said.

69George received these remarks in his usual wooden fashion.

70"Indeed, sir."

71"The personality of a criminal, Georges, is an interesting matter. Many murderers are men of great personal charm."

72"I always heard, sir, that Dr. Crippen was a pleasant-spoken gentleman. And yet he cut up his wife like so much mincemeat."

73"Your instances are always apt, Georges."

74The valet did not reply, and at that moment the telephone rang. Poirot took up the receiver.

75"'Allo—'allo—yes, yes, it is Hercule Poirot who speaks."

76"This is Knighton. Will you hold the line a minute, M. Poirot? Mr. Van Aldin would like to speak to you."

77There was a moment's pause, then the millionaire's voice came through.

78"Is that you, M. Poirot? I just wanted to tell you that Mason came to me now of her own accord. She has been thinking it over, and she says that she is almost certain that the man at Paris was Derek Kettering. There was something familiar about him at the time, she says, but at the minute she could not place it. She seems pretty certain now."

79"Ah," said Poirot, "thank you, M. Van Aldin. That advances us."

80He replaced the receiver, and stood for a minute or two with a very curious smile on his face. George had to speak to him twice before obtaining an answer.

81"Eh?" said Poirot. "What is that that you say to me?"

82"Are you lunching here, sir, or are you going out?"

83"Neither," said Poirot, "I shall go to bed and take a tisane. The expected has happened, and when the expected happens, it always causes me emotion."