"Now," he said, "we'll just go through the evidence which has been brought against these two men, Barthorpe and Burchill, which evidence has resulted in Barthorpe being committed for trial and in the police's increased anxiety to lay hold of Burchill. The police theory, after all, is a very simple one--let's take it and their evidence point by point. "1. The police say that Jacob Herapath came to his death as the result of a conspiracy between his nephew Barthorpe Herapath and Frank Burchill. "2. They say that the proof that that conspiracy existed is found in certain documents discovered by Davidge at Burchill's flat, in which documents Barthorpe covenants to pay Burchill ten per cent. of the value of the Herapath property if and when he, Barthorpe, comes into it. "3. The police argue that this conspiracy to murder Jacob Herapath and upset the will was in existence before November 12th--in other words that the idea of upsetting the will came first, and that the murder arose out of it. "4. In support of this they have proved that Barthorpe was in close touch with Burchill as soon as the murder was committed--afternoon of the same day, at any rate--and therefore presumably had been in close touch with him previously. "5. They have proved to the full a certain matter about which there is no doubt--that Barthorpe was at the estate office about the time at which, according to medical evidence, his uncle was murdered, that he subsequently put on his uncle's coat and hat and visited this house, and afterwards returned to the estate office. That, I say, is certain--and it is the most damning thing against Barthorpe. "6. According to the police, then, Barthorpe was the actual murderer, and Burchill was an accessory before the fact. There is no evidence that Burchill was near the estate office that night. But that, of course, doesn't matter--if, as the police suggest, there is evidence that the conspiracy to kill Jacob Herapath existed before November 12th, then it doesn't matter at all whether Burchill took an active part in it or not--he's guilty as accessory." The Professor here paused and smote his bundle of papers. Then he lifted and wagged one of his great fingers.