All this Len Mattern had heard of and had expected—though no amount of expectation could have braced him for that kind of reality. But there was more to it than he had heard, and it was the extra part that the second officer seemed curiously anxious to deny. "You saw nobody—nothing at the portholes," he told Mattern after that first Jump. "You just imagined it."
Mattern had been a spaceman long enough to be able to distinguish imagination from reality. Perhaps the creatures of hyperspace did live on planets, but it seemed they did not breathe the atmosphere of those planets as human beings breathe air, and so they were not confined to them. They could move around freely in the starless dusk of their universe. And, if there was a pact, then they must be intelligent creatures—though he would have known that anyway, for they spoke to him. He could hear them through the tight walls of the ship—less in his ears than his mind—cajoling, entreating, promising. And he shut his ears and his mind, because he was afraid.
At the end of the voyage, he was offered a permanent berth on the Perseus. "We don't usually take crewmen from the Far Planets," the second officer said thoughtfully. "They don't have the training needed. But you're a good deckhand."
Len waited tensely, not knowing whether he did want the job or not.
"The universe is opening up and sooner or later we're going to have to start diversifying our crews, take untrained men, maybe even—" the officer hesitated—"extraterrestrials. Sometimes training can restrict a man to the point where he can't think for himself. Main trouble with untrained men, though, is that often they've got too much imagination. They think things that aren't true, see things that aren't there."
"I understand, sir," Mattern said. "I'll keep my imagination stowed away until it's wanted."
From then on, he had seen no more at the ports than any of his properly conditioned mates.
IV
Len Mattern stayed with the Perseus over three years. Gradually, from things he observed himself, from things his shipmates told him, he learned what little there was to be known about hyperspace. Everything was different there from normspace; even the mechanical properties of things changed. However, Jumping was safe enough, as long as the spaceships didn't stop. As long as they were only passing through that other universe, they were, in a sense, not actually there, so that the elements of which they were composed would not change, although, to the senses, they seemed to.