By the end of a week Kayin was confident that he knew the language well enough to start reading it. He went to a public school which he found was open in the evenings, and there joined a class where someone explained the alphabet, and made clear to foreigners that English was a language full of traps and pitfalls. Kayin absorbed the information eagerly, but after the third lesson he found the pace much too slow, and did not return. He had never before encountered a language of so strange a structure, and the actual making of the sounds gave him trouble, but the basic principles of language study were as valid here as on his home planet, and he learned rapidly. By the end of a month he could read. By the end of the same month he had learned, too, the nature of the project on which he was working. On several occasions, the engineer in charge had passed by him to exchange a few words with the foreman and once with the man who had ordered the building. The words had been significant. There could be no mistake, for Kayin had come across them in his reading. “Laboratory” had a very definite meaning. And there were such expressions as “incubation tanks,” and “thermostat controls.” All in all, enough to let him know that they were engaged in constructing a plant for the manufacture of biochemical substances. He knew that there were biochemical plants already in existence, scattered over the civilized part of the planet, and the thought of great danger did not occur to him. But he continued, as the men around him would have put it, to keep his ears open, and as time went on he became more and more disquieted. * * * * * Meanwhile, his relations with the people among whom he worked became almost human. They greeted him every day as one of themselves, asked casual questions about the place from which he had come and the way he had lived, and accepted the answers as if with a quiet confidence that he was telling the truth. Once, in an access of good feeling, one of them had gone so far as to slap him amicably on the shoulder, and Kayin had experienced agony such as he had never felt before. But he managed to conceal the pain, and even to laugh weakly. He made sure, however, that a similar incident would never happen again. Whenever someone approached him too closely, he opened his extra eyes very slightly, ready to step aside at the touch of a too friendly hand. He had not realized how much his own attitude toward them had changed until the day an accident occurred. A large shelf of rock had unexpectedly turned up to block the excavation of a wide pit, and it had been necessary to shatter it with dynamite. But the explosive did not at first go off, and one of the men had gone back to see what was wrong. He had been just in time to be knocked down by the blast itself, and to be covered by the mass of dirt and broken rock that slid into the excavation.