“ ‘It’s a monstrous beast of prey!’ he croaked. ‘It can dissolve Time and reshape Time in a hundred horrible ways!’
“He quirked his head at me. ‘You know more than that lad but I know more than you—for I have lived through this moment before! Once long ago I stood in this cave and warned you! You are at the crossroads of a branching future! If you take the right turn now you will live to become me. But, if you take the wrong turn—’
“He straightened, and pointed with his gloved forefinger into the shadows behind me. ‘It is there—at your back! When you turn you will see the shining web which it uses to dissolve Time! All over this valley the creature has thrown a Time-dissolving web of force!’
“His voice rose warningly. ‘It is as intelligent as we are, but it moves with glacial slowness. An inch in an hour—a foot in a day! When it dissolves Time it nourishes itself by drawing the energy-whirl into itself, and spinning it out again in another form, like an immense, living shuttlecock. A spider—’
“He looked at me with a haggard intensity of appeal. ‘It will try to hold you with the web—to hold you in complete helplessness until you become a hundred lads and a hundred men. You’ll be an infant, a boy of five, a lad of twenty, and a man older than myself. But every time you split up in the folds of the web you’ll lose a part of your substance.
“ ‘You’ll cease to be a man with a past and a future. You’ll become a mere hollow shell—no more substantial than I am, and I am little more than a wraith. You’ll be drained, and you’ll vanish like a puff of smoke. You’ll be devoured and swallowed up!’
“He was struggling for breath and the veins on his forehead had begun to swell. ‘You’ve got to blast it down before the web dazzles and confuses you! You’ll have to face it to blast, but if you fight it with your mind—’
“Suddenly the helmet was back on his head and he was turning from me. He moved straight toward the lad and put a palsied hand on the shoulder of that younger me.
“Then, slowly, they both turned to face me, and I could see their eyes inside their helmets, trained upon me in desperate appeal. At least—there was appeal in the eyes of the old one. The lad may have been merely terrified, and confused.
“He couldn’t have been more terrified than I was as the shadows lengthened about me, and a coldness crept into my bones.
“I knew I’d have to come to grips with the web. I knew, too, that if it was behind me I’d be safer facing it. When there’s something unspeakable at your back, you can die so many deaths just waiting for it to make its presence known that all the courage and decision goes out of you.
“Panic smote me as I turned, hip and thigh like a flat sword. But all I could see for an instant was a faint, moving radiance blending with the shadows, a kind of nebulous flowing in the darkness on the far side of the cave.
“My hand must have closed on my blaster, for I could feel the bite of cold metal against my palm. But there was something about the light that my will could not withstand. My arms seemed to freeze as I stared at it, and terrifying thoughts rushed into my brain.
“At first I experienced only a feeling of almost unbearable oppression. Then something in the glow seemed to reach out toward me and there was no sound in the cave but the beating of my heart.
“A ghastly something seemed to be watching me with a kind of fiendish triumph, as though the soul of a devil lurked in the depth of the light which could send out vampire tendrils, filmed with writhing menace.
“I couldn’t tear my eyes from the glow and the longer I stared the worse it got.
“The light seemed filled with an evil purpose. It writhed and changed shape as I stared at it, seeming to sweep out through the walls of the cave and back again with a pulsing greediness.
“Then, gradually, it ceased to blend with the shadows. It became stationary and transparent, hanging suspended in the murky air like a gigantic burning glass.
“As though in a dream-delirium I became slowly aware that a picture was forming within it. A valley swept into view, walled with high, saw-toothed mountain ranges.
“Deep in the weaving radiance I could see a tiny, plodding figure coming toward me across the valley.
“For an instant I thought I was looking at the far-off image of a human figure plodding over the plain. A figure clad in a heavy spacesuit, moving awkwardly—as I had moved.
“Nearer it came and nearer, its reflection floating on ahead of it, bobbing about like a little ship.
“And then, suddenly, I saw that it was skimming the plain. It was balancing itself on flapping wings, sweeping across the plain without actually touching it, but so slowly that it appeared to be advancing with the plodding, awkward gait of a man.
“It swerved abruptly as I stared, made a full turn, and soared into the air. It flew straight toward me, its wings beating the air as though it were struggling against a furious uprush of wind.
“There was a sloping wall of light-dappled rock at the edge of the radiance, and for an instant the winged shape disappeared behind it. I didn’t see it descend.
“I saw only a shadow forming behind the rock, and swirling out from it. It came into view again abruptly, dragging its wings behind
