Wolfe shook his head. “You may not need it; if you do, you may have it when the time comes. Another assumption, that Mr Rony was not upright when the car hit him, also got confirmed. Although the car had not struck his head, there was a severe bruise above his right ear; a doctor hired by me saw it, and it is recorded on the official report. That helped to acquit the murderer of so slapdash a method as trying to kill a lively and vigorous young man by hitting him with a car. Obviously it would have been more workmanlike to ambush him as he walked up the drive, knock him out, and then run the car over him. If that-” “You can't ambush a man,” Ben Dykes objected, “unless you know he'll be there to ambush.” “No,” Wolfe agreed, “nor can you expect me ever to finish if you take no probabilities along with facts. Besides the private telephone lines in Mr Sperling's library there are twelve extensions in that house, and Miss Sperling's talk with Mr Rony, arranging for his arrival at a certain hour for a rendezvous on the grounds, could have been listened to by anyone. William Reynolds could certainly have heard it; let him prove he didn't. Anyhow, the ambush itself is no longer a mere probability. By a brilliant stroke of Mr Goodwin's, it was established as a fact. On Thursday he searched the grounds for the instrument used for laying Mr Rony out, and he found it, in the presence of a witness.” “He didn't!” It was Madeline's voice from behind me. “I was with him every minute and he didn't find anything!” “But he did,” Wolfe said dryly. “On his way out he stopped at the brook and found a stone. The question of the witness, and of the evidence that the stone had been in contact with a man's head, can wait, but I assure you there's no doubt about it. Even if the witness prefers to risk perjury we'll manage quite well without her.” His eyes made an arc to take them in. “For while such details as the head bruise and the stone will be most helpful and Mr Archer will be glad to have them, what clinches the matter is a detail of a different sort. I have hinted at it before and I now declare it: William Reynolds, the owner of that card, the Communist, is in this room. You won't mind, I hope, if I don't tell you how I learned it, so long as I tell you how I can prove it, but before I do so I would like if possible to get rid of a serious embarrassment. Mr Kane. You're an intelligent man and you see my predicament. If the man who murdered Mr Rony is charged and put on trial, and if that statement you signed is put in evidence by the defence, and you refuse to repudiate it, there can be no conviction. I appeal to you: do you want to furnish the shield to a Communist and a murderer? No matter who he is. If you are reluctant to credit my assertion that he is a Communist, consider that unless that can be proven to the satisfaction of a judge and jury he will not be in jeopardy, for that is essential to the case against him. But as long as your statement stands it would be foolhardy even to arrest him; Mr Archer wouldn't dare to move for an indictment.” Wolfe got a paper from a desk drawer. “I wish you would sign this. It was typed by Mr Goodwin this evening before you came. It is dated today and reads, ‘I, Webster Kane, hereby declare that the statement signed by me on June twenty-first, nineteen forty-nine, to the effect that I had killed Louis Rony accidentally by driving an automobile over him, was false. I signed it at the suggestion of James U. Sperling, Senior, and I hereby retract it.’ Archie?” I got up to reach for the paper and offer it to Kane, but he didn't move a hand to take it. The outstanding economist was in a hole, and his face showed that he realized it.