Elvin walked back to the Schermerhorn ranch, enjoying the noon-day warmth. San Benedicto was crowded with Saturday shoppers. He met his students everywhere, and always they commented on the practical joke he had played on them. By the time he was back in his room, the fiction of the joke was thoroughly established in his own mind. He almost believed it himself. He glanced again at the transparent cylinder of spheres. A chemist might be able to analyze the contents and say where the jar had originated. Perhaps Miss Gerkin could do it. She had taught science for more than twenty years at San Benedicto High. Yet Elvin knew he couldn't ask her for help. If the colored balls turned out to be nothing more than hard candy, then by inescapable logic he would have to accept the fact that he was suffering from a major hallucination. It was more comfortable not to know the truth. The idea of candy, however, brought up another association. Mrs. Schermerhorn had said that earlier in the evening Bill Blake had won a jar of candy as a prize. Bill Blake was the prize joker of the tenth grade. Elvin had what seemed to be an intuitive flash of understanding. The rocket had been a joke, all right, but it had been aimed at Elvin. The kids had rigged it up before he came home from the show. During the night they had come back and taken the stage setting away. * * * * * Elvin spent the rest of the weekend planning his revenge. He didn't think of it as that, but rather disciplinary action. Yet he knew the class would get the point and possibly even heed the implied warning. In five years Elvin had reduced the complex process of teaching to one workable rule: break the class, or the kids will break you. Now he chose the classical cat-whip of a surprise test to crack them back into line. He spent Sunday planning it and duplicating the pages. He was scrupulously careful to be fair--at least as he defined the term. The examination covered nothing that had not been discussed in class. But Elvin taught grammar, and no field of the abstract allows such devious application of the flimsy nonsense passing for rules. On Monday morning, with a thin smile, Elvin was ready for them. He had tenth grade English first period. As he passed out the mimeographed pages, he waited for waves of groaning to sweep the room. Nothing happened. He felt an annoying pang of anger. A hand shot up. "Yes, Charles?" he snapped. "If we finish before the end of the period, can we have free reading?" "I doubt you'll finish, Charles. This test is ten pages long." "But if we do--" "By all means, yes."