The professor hopped into the machine and began preparing it for another trip. "Now as to what happened to me. Once you--You I again--prevented You II from moving that rock, you immediately precipitated--not so much a change as a--an _unchange_ in my personal situation. The rock had not been shifted--therefore, I had not been married, was not married, and, let us hope, will never be married. I was also no longer bald. But, by the very fact of the presence of the two You's in the past, by virtue of some microscopic form of life you killed with your breath, let us say, or some sand you impressed with your feet,--sufficient alterations were made right through to the present so that my name was (and always had been!) Roodles and your name--" "Is probably MacTavish by now," McCarthy yelled. "Look prof, are you through with the machine?" "Yes, it's all ready." The professor grimaced thoughtfully. "The only thing I can't place is what happened to that camera you said I took from you. Now if You I in the personification of You II--" McCarthy planted his right foot in the small of the little man's back and shoved. "I'm gonna get this thing settled and come back and never, never, _never_ go near one of these dinguses again!" He yanked at the chronotransit. The last he saw of the professor was a confused picture of broken glassware, tangled electrical equipment and indignantly waving white hair. * * * * * This time he materialized at the very edge of the beach. "Gettin' closer all the time," he mumbled as he stepped out of the housing. Now to hand over the note, then-- Then-- "Great sufferin' two-tailed explodin' catfish!" There were two men fighting near a red rock. They wore identical clothes; they had identical features and physical construction, including the same lanky forms and long, stringy necks. They fought in a weird pattern of mirror-imagery--each man swinging the same blows as his opponent, right arm crossing right, left crossing left. The man with his back to the rock had an expensive miniature camera suspended from his neck; the other one hadn't. Suddenly, they both feinted with their lefts in perfect preparation for what hundreds of railroad bulls had come to curse as "the Gooseneck McCarthy One-Two." Both men ignored the feint, both came up suddenly with their right hands and-- They knocked each other out. They came down heavily on their butts, about a yard apart, shaking their heads. "You are the stubbornest cuss I ever saw," one of them began. "Where--" "--did you learn my punch?" McCarthy finished, stepping forward. They both sprang to their feet, stared at him. "Hey," said the man with the camera. "You two guys are twins." His former opponent differed with him. "You mean _you_ two guys are twins!"