"No," I said. "I see that. You have so far been able to find no connection between these varying cases?"

Poirot shook his head.

"Nothing."

I reflected again. In the A.B.C. crimes, we had to deal with what purported to be an alphabetical series, though in actuality it had turned out to be something very different.

I asked:

"There is, you are quite sure, no farfetched financial motive - nothing, for instance, like you found in the case of Evelyn Carlisle?"

"No. You may be quite sure, my dear Hastings, that financial gain is the first thing for which I look."

That was true enough. Poirot has always been completely cynical about money. I thought again. A vendetta of some kind? That was more in accordance with the facts. But even there, there seemed a lack of any connecting link. I recalled a story I had read of a series of purposeless murders - the clue being that the victims had happened to serve as members of a jury, and the crimes had been committed by a man whom they had condemned. It struck me that something of that kind would meet this case. I am ashamed to say that I kept the idea to myself. It would have been such a feather in my cap if I could go to Poirot with the solution. Instead I asked: "And now tell me, who is X?"

To my intense annoyance Poirot shook his head very decidedly.

"That, my friend, I do not tell." "Nonsense. Why not?" Poirot's eyes twinkled.

"Because, mon cher, you are still the same old Hastings. You have still the speaking countenance. I do not wish, you see, that you should sit staring at X with your mouth hanging open, your face saying plainly: 'This - this that I am looking at is a murderer.' "

"You might give me credit for a little dissimulation at need."

"When you try to dissimulate, it is worse. No, no, mon ami, we must be very incognito, you and I. Then, when we pounce, we pounce."

"You obstinate old devil," I said. "I've a good mind broke off as there was a tap on the door. Poirot called, "Come in," and my daughter Judith entered. I should like to describe Judith, but I've always been a poor hand at descriptions. Judith is tall, she holds her head high, she has level dark brows and a very lovely line of cheek and jaw - severe in its austerity. She is grave and slightly scornful, and to my mind there has always hung about her a suggestion of tragedy. Judith didn't come and kiss me - she is not that kind. She just smiled at me and said, "Hullo, Father."

Her smile was shy and a little embarrassed, but it made me feel that in spite of her undemonstrativeness she was pleased to see me.

"Well," I said, feeling foolish as I so often do with the younger generation, "I've got here."

"Very clever of you, darling," said Judith.