, but the Degravitational Unit made his escape easy. Within
four hours he was back in San Benedicto. He hurried to the workshop. But
when he pounded on the door, there was no response. He tried the latch
and the door swung open.

The room was empty, but on the table was a large envelope addressed to
him. A thin thread of wire was fastened to it; as he picked it up, the
wire broke and somewhere in the distance a motor began to hum.

"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