"You've got the connection between all these different cases?"

"I think so."

"Well, then."

I could hardly restrain my impatience.

"No, Hastings."

"But I've got to know."

"It is much better that you should not."

"Why?"

"You must take it from me that it is so." "You are incorrigible," I said. "Twisted up with arthritis. Sitting here helpless. And still trying to play a 'lone hand.' "

"Do not figure to yourself that I am playing a lone hand. Not at all. You are, on the contrary, very much in the picture, Hastings. You are my eyes and my ears. I only refuse to give you information that might be dangerous."

"To me?"

"To the murderer."

"You want him," I said slowly, "not to suspect that you are on his track? That is it, I suppose. Or else you think that I cannot take care of myself."

"You should at least know one thing, Hastings. A man who has killed once will kill again - and again and again and again."

"At any rate," I said grimly, "there hasn't been another murder this time. One bullet at least has gone wide."

"Yes, that was very fortunate - very fortunate indeed. As I told you, these things are difficult to foresee."

He sighed. His face took on a worried expression.

I went away quietly, realizing sadly how unfit Poirot was now for any sustained effort. His brain was still keen, but he was a sick and tired man. Poirot had warned me not to try to penetrate the personality of X. In my own mind I still clung to my belief that I had penetrated that personality. There was only one person at Styles who struck me as definitely evil. By a simple question, however, I could make sure of one thing. The test would be a negative one, but would nevertheless have a certain value.

I tackled Judith after breakfast.

"Where had you been yesterday evening when I met you, you and Major Allerton?"

The trouble is that when you are intent on one aspect of a thing, you tend to ignore all other aspects. I was quite startled when Judith flared out at me.

"Really, Father, I don't see what business it is of yours." I stared at her, rather taken aback.

"I - I only asked."

"Yes, but why? Why do you have to be continually asking questions? What was I doing? Where did I go? Who was I with? It's really intolerable!" The funny part of it was, of course, that this time I was not really asking at all where Judith was. It was Allerton I was interested in.

I tried to pacify her.

Really, Judith, I don't see why I can't ask a simple question."

"I don't see why you want to know."

"I don't particularly. I mean, I just wondered why neither of you - er - seemed to know what had happened."

"About the accident, do you mean? I'd been down to the village, if you must know, to get some stamps." I pounced on the personal pronoun. "Allerton wasn't with you then?" Judith gave an exasperated gasp.