‘There were three things that I could not fit into the pattern,’ said Alleyn, and he spoke more to Troy than to Mildred. ‘It seemed at first that if Dimitri overheard the telephone call he had an overwhelming motive. We knew he was a blackmailer, and we knew Bunchy was on his track. But we found that Dimitri literally could not have done the murder. His alibi stood up to the time factor and came out on top.

‘Withers is a bad lot, and Bunchy knew that too, but somehow I could not see Withers as the killer. He’s hard, wary and completely unscrupulous. If he did ever murder it would be deliberately, and with forethought. The whole thing would be worked out to the last second. This job was, we believed, unpremeditated until within two and a half hours of its execution. Still Withers had to be considered. There was a gap in his alibi. I now know that he spent that gap driving his woman-dupe about in his car in order to discuss a situation which had become acute. Into this department, and again I implore your silence because I certainly shouldn’t tell you about it, came old General Halcut-Hackett like an elderly harlequin dodging about in the fog of Belgrave Square at the crucial time when the guests left Marsdon House. He, of course, was looking for his wife. Next came Carrados. Old Carrados was an infernal bore. His alibi, which overlapped Dimitri’s, held good, but his behaviour was rum in the extreme. It was not until I heard of an incident eighteen years old that I managed to fit him into the pattern. And all the time there were three things about Davidson for which I could find only one explanation. He told me he saw a certain cigarette-case in the green sitting-room at about eleven-thirty. Certainly not later. We found that the cigarette-case in question was only in this room for about four minutes round about one o’clock during which the telephone conversation took place. Why should Davidson lie? He had thought the case was a set-piece—one of the Marsdon House possessions; he had not realized that it was the personal property of one of the guests. He stated most emphatically that he did not overhear the conversation and indeed did not return to the room after eleven-thirty. But there is a curious point about the telephone conversation. Bunchy said to me: “He might as well mix his damn brews with poison.” Davidson must have overheard that sentence because it came just before Bunchy broke off. Bunchy was talking about Dimitri, of course, but I believe Davidson thought he was talking about him. The broken sentence: “with such filthy ingenuity,” or something of that sort. Davidson probably thought the next word Bunchy spoke would be his (Davidson’s) name. That’s odd, isn’t it?