"Shut up, everybody!" Dave ordered, clapping his hands to his face. When he dropped them a moment later his eyes gleamed. "I got it now! Angler figured they were using the latest edition of MCO to program the Machine on openings, he found an editorial error and then he deliberately played the Machine into that variation!" Dave practically shouted his last words, but that attracted no attention as at that moment the whole hall was the noisiest it had been throughout the tournament. It simmered down somewhat as the Machine flashed a move. Angler replied instantly. The Machine replied almost as soon as Angler's move was fed into it. Angler moved again, his move was fed into the Machine and the Machine flashed: I AM CHECKMATED. CONGRATULATIONS! VIII Next morning Sandra heard Dave's guess confirmed by both Angler and Great. Doc had spotted them having coffee and a malt together and he and Sandra joined them. Doc was acting jubilant, having just drawn his adjourned game with Sherevsky, which meant, since Jandorf had beaten Grabo, that he was in undisputed possession of Ninth Place. They were all waiting for the finish of the Votbinnik-Lysmov game, which would decide the final standing of the leaders. Willie Angler was complacent and Simon Great was serene and at last a little more talkative. "You know, Willie," the psychologist said, "I was afraid that one of you boys would figure out something like that. That was the chief reason I didn't have the Machine use the programmed openings until Lysmov's win forced me to. _I_ couldn't check every opening line in MCO and the _Archives_ and _Shakhmaty_. There wasn't time. As it was, we had a dozen typists and proofreaders busy for weeks preparing that part of the programming and making sure it was accurate as far as following the books went. Tell the truth now, Willie, how many friends did you have hunting for flaws in the latest edition of MCO?" Willie grinned. "Your unlucky 13th. Well, that's my secret. Though I've always said that anyone joining the Willie Angler Fan Club ought to expect to have to pay some day for the privilege. They're sharp, those little guys, and I work their tails off." Simon Great laughed and said to Sandra, "Your young friend Dave was pretty sharp himself to deduce what had happened so quickly. Willie, you ought to have him in the Bleeker Street Irregulars." Sandra said, "I get the impression he's planning to start a club of his own." Angler snorted. "That's the one trouble with _my_ little guys. They're all waiting to topple me." Simon Great said, "Well, so long as Willie is passing up Dave, I want to talk to him. It takes real courage in a youngster to question authority." "How should he get in touch with you?" Sandra asked. While Great told her, Willie studied them frowningly. "Si, are you planning to stick in this chess-programming racket?" he demanded.