"And then?" asked Katherine in a low voice.

"And then," Derek shrugged his shoulders, "Ruth was murdered-very providentially."

He laughed, and the sound of his laugh hurt Katherine. She winced.

"Yes," said Derek. "that wasn't in very good taste. But it is quite true. Now I am going to tell you something more. From the very first moment I saw you I knew you were the only woman in the world for me. I was -afraid of you. I thought you might bring me bad luck."

"Bad luck?" said Katherine sharply.

He stared at her. "Why do you repeat it like that? What have you got in your mind?"

"I was thinking of things that people have said to me."

Derek grinned suddenly. "They will say a lot to you about me, my dear, and most of it will be true. Yes, and worse things too- things that I shall never tell you. I have been a gambler always-and I have taken some long odds. I shan't confess to you now or at any other time. The past is done with. There is one thing I do wish you to believe. I swear to you solemnly that I did not kill my wife."

He said the words earnestly enough, yet there was somehow a theatrical touch about them. He met her troubled gaze and went on: "I know. I lied the other day. It was my wife's compartment I went into."

"Ah," said Katherine.

"It's difficult to explain just why I went in, but I'll try. I did it on an impulse. You see, I was more or less spying on my wife.

I kept out of sight on the train. Mirelle had told me that my wife was meeting the Comte de la Roche in Paris. Well, as far as I had seen, that was not so. I felt ashamed, and I thought suddenly that it would be a good thing to have it out with her once and for all, so I pushed open the door and went in."

He paused.

"Yes," said Katherine gently.

"Ruth was lying on the bunk asleep-her face was turned away from me-I could only see the back of her head. I could have waked her up, of course. But suddenly I felt a re- sction. What, after all, was there to say that w^ hadn't both of us said a hundred times before? She looked so peaceful lying there. I left the compartment as quietly as I could." amp; "Why lie about it to the police?" asked Katherine.

"Because I'm not a complete fool. I've realized from the beginning that, from the point of view of motive, I'm the ideal murderer.

If I once admitted that I had been in her compartment just before she was murdered, I'd do for myself once and for all."

"I see."

Did she see? She could not have told herself.

She was feeling the magnetic attraction of Derek's personality, but there was something in her that resisted, that held back…

"Katherine-"

"You know that I care for you. Do-do you care for me?"»

"I-I don't know."

Weakness there. Either she knew or she did not know.

If-if only-She cast a look round desperately as though seeking something that would help her. A soft colour rose in her cheeks as a tall fair man with a limp came hurrying along the path towards them-Major Knighton.

There was relief and an unexpected warmth in her voice as she greeted him.

Derek stood up scowling, his face black as a thundercloud.

"Lady Tamplin having a flutter?" he said easily. "I must join her and give her the benefit of my system."

He swung round on his heel and left them together. Katherine sat down again. Her heart was beating rapidly and unevenly, but as she sat there talking commonplaces to the quiet, rather shy man beside her, her selfcommand came back.

Then she realized with a shock that Knighton also was laying bare his heart, much as Derek had done, but in a very different manner.

He was shy and stammering. The words came haltingly with no eloquence to back them.

"From the first moment I saw you-I-I ought not to have spoken so soon-but Mr. Van Aldin may leave here any day, and I might not have another chance. I know you don't care for me so soon-that is impossible.

I dare say it is presumption anyway on my part. I have private means, but not very much-no, please don't answer now. I know what your answer would be. But in case I went away suddenly I just wanted you to know-that I care."

She was shaken-touched. His manner was so gentle and appealing.

"There's one thing more. I just wanted to say that if-if you are ever in trouble, anything that I can do-"

He took her hand in his, held it tightly for a minute, then dropped it and walked rapidly away towards the Casino without looking back.

Katherine sat perfectly still, looking after him. Derek Kettering-Richard Knighton -two men so different-so very different. There was something kind about Knighton, kind and trustworthy. As to Derek-Then suddenly Katherine had a very curious sensation. She felt that she was no longer sitting alone on the seat in the Casino gardens, but that some one was standing beside her, and that that some one was the dead woman, Ruth Kettering. She had a further impression that Ruth wanted-badly-to tell her something. The impression was so curious, so vivid, that it could not be driven away. She felt absolutely certain that the spirit of Ruth Kettering was trying to convey something of vital importance to her. The impression faded. Katherine got up, trembling a little. What was it that Ruth Kettering had wanted so badly to say?

When Knighton left Katherine he went in search of Hercule Poirot, whom he found in the Rooms, jauntily placing the minimum stake on the even numbers. As Knighton joined him, the number thirtythree turned up, and Poirofs stake was swept away.

"Bad luck!" said Knighton; "are you going to stake again?"

Poirot shook his head.

"Not at present."

"Do you feel the fascination of gambling?" asked Knighton curiously.

"Not at roulette."

Knighton shot a swift glance at him. His own face became troubled. He spoke hautily, with a touch of deference. "I wonder, are you busy, M. Poirot? There is something I would like to ask you about."

attitude that I went down privately and had an interview with the lady."

"Eh bien?"

"The difficulty was that she insisted on seeing Mr. Van Aldin himself. I softened his message as much as I possibly could. In fact-to be candid-I gave it in a very different form. I said that Mr. Van Aldin was too busy to see her at present, but that she might make any communication she wished to me. That, however, she could not bring herself to do, and she left without saying anything further. But I have a strong impression, M. Poirot that that woman knows something."

"This is serious," said Poirot quietly.

"You know where she is staying?"

"Yes." Knighton mentioned the name of the hotel.

"Good," said Poirot; "we will go there immediately."

The secretary looked doubtful.

"And Mr. Van Aldin?" he queried doubtfully.

"M. Van Aldin is an obstinate man," said Poirot drily. "I do not argue with obstinate men. I act in spite of them. We will go and see the lady immediately. I will tell her that you are empowered by M. Van Aldin to act for him, and you will guard yourself well from contradicting me."

Knighton still looked slightly doubtful, but Poirot took no notice of his hesitation.

At the hotel, they were told that Mademoiselle was in, and Poirot sent up both his and Knighton's cards, with "From Mr. Van Aldin" pencilled upon them.

Word came down that Mademoiselle Mirelle would receive them.

When they were ushered into the dancer's apartments, Poirot immediately took the lead.

"Mademoiselle," he murmured, bowing very low, "we are here on behalf of M. Van Aldin."

"Ah! And why did he not come himself?"

"He is indisposed," said Poirot mendaciously;

"the Riviera throat, it has him in its grip, but me, I am empowered to act for him, as is Major Knighton, his secretary.