"Dear Mr. Elvin," he read. "It was unkind of us to play another trick on you, but we're sure you'll be clever enough to steal the tungsten without getting caught. When you came to talk to us, we realized that the conclusion we had reached was right. Children--adolescent minds--have wrecked our world. You know all about that, Mr. Elvin; teachers always do. And you've told us so often in class about the unstable emotions of adolescents, their tantrums, their unpredictability, their unsocial behavior, their egocentricity and all the rest. We'd like to help, but there isn't much we can do, not really; you just want the machines we know how to make, not the ideas we've learned. We grew up, you see, on the day we turned the desert to gold. We found out what happens when you give children dangerous toys to play with. "We made our mistake, and we know how to straighten it out. We've only waited for you to read this so that you would understand, at least for a moment. We have isolated ourselves in suspended time; we're right here in the workshop with you, but you can't see us, naturally, because we started standing still in time more than an hour ago. When you opened your envelope, you tripped the motor of a matter transposition machine which will throw all time backward to last Friday night. None of this will have happened then. That should straighten everything out, don't you think? "You'll find the rocket again, and you'll open it, just as you did before. But this time there'll be only a jar of bubble gum inside, because we've already consumed the learning capsules. There won't be any memory left for anyone--except ours. We've learned how to work with a planet of adolescents. We think we can help you mature in spite of yourselves; but this time no one will ever know how it is being done." Elvin looked up, but before the anger and frustration could crystalize in his mind, the yellow lamp dimmed, the walls of the workshop faded and vanished. He fought for a moment against the blackness rising in his mind. The light paled and paled and finally it was nothing more than a red streak in the sky. It moved closer and he saw that it was a falling object followed by a long plume of red flame. It flashed momentarily overhead and Elvin heard a dull thud as it fell in a field beyond the ranch house. He sprang up from the couch and moved off in the darkness. It had been a meteorite, of course; if it had survived the friction of the atmosphere, it would make an interesting exhibit for the science classroom....