"But all the while the sanest part of my mind was seeking an explanation that would one-tenth explain it! I gripped my own boy-self by the shoulder to make sure he'd stay solid until the man he'd become could get a mental toe-hold on the problem.
"If you can persuade a man to mount a stepladder and plant himself firmly on the air you've taken your first brave step into the unknown. The poor devil may or may not fall. But at least you've made a start in the right direction.
"It isn't too hard to believe that certain things can happen to Time on the wrong side of yesterday—or tomorrow! Time—the physicists tell us—never stops flowing. It's like a melting candle or silk before it hardens on the loom—all crinkled up and sparkling like a dew-drenched spider web.
"If Time melts in a back-of-yesterday dimension what's to stop a man from dissolving with it, and running in a thin trickle back to his yesterdays? You were a boy once and you could be a boy again—without ceasing to be a man.
"Put it this way. On the dark side of the moon there was a valley of shadows. A big, blundering fool went stumbling into it, and landed in a heap. Before he could pick himself up a part of himself dissolved in some unimaginable backwash of time, and he became a boy again. His boy-self split off from him, and went stumbling off over the plain in a suit five sizes too large for him.
"It's not as impossible as it sounds. The boy you were still exists in Time, and he could emerge from the past to stand beside you in a vortex of dissolving Time. Was there something in the valley that could change the flow of time, reverse it, and twist it around like butter in a churn?
"The answer was right there in the cave with me. But I couldn't see it because another space-suited figure was making my brain whirl. He'd come clumping into the cave bent nearly double, and now he was shuffling toward me as though I'd committed some horrible crime I could never hope to atone for.
"Through the pane of his helmet his eyes burned accusingly into mine. But it wasn't until he halted directly in front of me and lifted the helmet from his head that I knew what my crime was and why he found it hard to forgive me.
"I had committed the crime of living beyond my alloted span! The man facing me was old ... old. His face was still my face, but if ever I had been young and handsome and a target for the wiles of a pretty woman I was so no longer!
"He seemed to realize that I could hardly bear to look upon myself as I would be, for he spoke sharply, quickly, without attempting to explain his presence, or even to prepare me for what he had to say by working up to it like a story-teller with a great load of unimaginable horror on his mind.