te:

_The theory contains within itself the proof that the universe must, by
logical necessity, be constructed according to said theory. But
observation and experience say this is not true._

He frowned at what he had written. This was the conclusion to which he
had led both men. It was the conclusion upon which he had rested. They,
obviously, had not rested there. They had gone on.

Under what he had written he wrote "_Either_:" on the left hand margin.
Two inches under it he wrote, "_Or_:" Then he frowned at them. Suddenly
he began writing rapidly after the _Either_: "_The universe is not
constructed according to logical necessity._"

He hesitated, studying what he had written. Then, pursing his lips, he
slowly wrote after the _Or_: "_The observable universe is not the
universe._"

He nodded to himself. That hit at the core of the matter. A was X. B was
not X. Therefore B was not A. Even though A and B were both called
universe.

The question was, then--did the universe-of-logical-necessity exist? If
so, what relationship did it have to the observable universe which quite
obviously did exist?

Was that the question, the answer to which, gained in a moment of
insight, had caused two men to utterly vanish?

He sighed with real regret. There was no way of knowing. Possibly a
mechanical brain of the most advanced type could come out with a
comprehensive picture after solving thousands of successive equations.
Knowledge of simple basics was a far cry from a fully expanded system.

He pushed the sheet of paper away with a show of irritation. He was
missing something. He was on the wrong track. Neither John nor Horace
had the mental equipment to make more than a simple step beyond what he
had accomplished. That was certain. It was equally certain that he could
and would make it.

A startled expression appeared on his face. "Oh good lord!" he groaned.
"My book. I must do something about that the first thing tomorrow. I--"
He opened the drawer of his desk and took out an oblong of paper, the
check against advance royalties. "I'll return this and not let them
publish it. First thing in the morning. And from now on I resolve not to
think of my theory or what caused John and Horace to vanish."

Folding the check neatly, he stuck it in his billfold and then started
to read a book that interested him. He became engrossed in it. Half an
hour later he came to enough to realize he was on safe ground, sigh with
relief, an