I sat down beside him, and made a last check over the contents of our car.

Now — as we sat there, in a startling second — the walls of our apartment melted, silently, to glass! All around us, visible now through the translucent walls of our room, the bleak plains of White Earth stretched off to the distance, gilded red by an advanced sunset. The Constructor’s cilia — again to Nebogipfel’s specification — had reworked the material of the walls of the chamber within which the Time-Car sat. We should continue to need some protection from the savage climate of White Earth; but we wished to have a view of the world as we progressed.

Although the temperature of the air was unchanged, I immediately felt much colder; I shivered, and pulled my coat closer around me.

“I think we are set,” Nebogipfel said.

“Set,” I agreed “save for one thing — our decision! Do we travel to the future of the completed Ships, or—?”

“I think the decision is yours,” he said. But he had — I like to think — some sympathy in his alien expression.

Still that soft fear quivered inside me, for, save for those first few desperate hours after I lost Moses, I have never been a man to welcome the prospect of death! — and yet I knew that my choice now might end my life. But still -

“I really don’t think I have much choice,” I told Nebogipfel. “We cannot stay here.”

“No,” he said. “We are exiles, you and I,” he said. “I think there is nothing for us to do but continue — on to the End.”

“Yes,” I said. “To the End of Time itself, it seems… Well! So be it, Nebogipfel. So be it.”

Nebogipfel pressed forward the levers of the Time-Car — I felt my breathing accelerate, and blood pounded in my temples — and we fell into the gray clamor of time travel.

Once more the sun rocketed across the sky, and the moon, still green, rolled through its phases, the months going by more quickly than heartbeats; soon, the velocities of both orbs had increased to the point where they had merged into those seamless, precessing bands of light I have described before, and the sky had taken on that steely grayness which was a compound of day and night. All around us, clearly visible from our elevated viewpoint, the ice-fields of White Earth swept away and over the horizon, all but unchanging as the meaningless years flapped past, displaying only a surface sheen smoothed over by the rapidity of our transition.

I should have liked to have seen those magnificent interstellar sail-craft soar off into space; but the rotation of the earth rendered those fragile ships impossible for me to make out, and as soon as we entered time travel the sail-ships became invisible to us.

Within seconds of our departure — as seen from our diluted point of view — our apartment was demolished. It vanished around us like dew, to leave our transparent blister sitting isolated on the flat roof of our tower. I thought of our bizarre, yet comfortable, set of chambers — with my steam-bath, that ludicrous flock wallpaper, the peculiar billiards table, and all the rest — all of it had been melted back, now, into general formlessness, and our apartment, no longer required, had been reduced to a dream: a Platonic memory, in the metal imagination of the Universal Constructors!

But we were not abandoned by our own, patient Constructor, however. From my accelerated point of view I saw how he seemed to rest here, a few yards from us — a squat pyramid, the writhing of his cilia smoothed over by our time passage — and then he would jump, abruptly, to there, to linger for a few seconds — and so on. Since a mere second for us lasted centuries in the world beyond the Time-Car, I could calculate that the Constructor was remaining close to our site, all but immobile, for as much as a thousand years at a time.

I remarked on this to Nebogipfel. “Imagine that, if you can! To be Immortal is one thing, but to be so devoted to a single task… He is like a solitary Knight guarding his Grail, while historical ages, and the mayfly concerns of ordinary men, flutter away.”

As I have described, the buildings which neighbored ours were towers, standing two to three miles apart, all across the Thames valley. In the several weeks we had spent in our apartment I had seen no evidence of change about these towers — not even the opening of a door. Now, though, with the benefit of my accelerated perceptions, I saw how slow evolutions crept over the buildings’ surfaces. One cylindrical affair in Hammersmith had its mirror-smooth face swell up, as if raddled by some metallic disease, before settling into a new pattern of angular bumps and channels. Another tower, in the vicinity of Fulham, disappeared altogether! — One moment it was there, the next not, without even the shadow of foundations on the ground to show where it had been, for the ice closed over the exposed earth more rapidly than I could follow.

This sort of flowing evolution went on all the time. The pace of change in this new London must be measured in centuries, I realized — rather than the years within which sections of my own London had been transformed — but change there was, nevertheless.

I pointed this out to Nebogipfel.

“We can only speculate as to the purpose of this rebuilding,” he said. “Perhaps the change in outer appearance signifies a change in inner utilization. But the slow processes of decay are working even here. And perhaps there are, occasionally, more spectacular incidents, such as the fall of a meteorite.”

“Surely intelligences so vast as these Constructors could plan for such accidents as the fall of a meteor! — by tracking the falling rocks with their telescopes, perhaps using their Ships with rockets and sails to knock the things away.”

“To some extent. But the solar system is a random and chaotic place,” Nebogipfel said. “One could never be sure of eliminating all calamities, no matter what resources were available, and no matter what planning and watching was performed… And so, even the Constructors must sometimes rebuild — even the tower we inhabit.”

“What do you mean?”

“Think it out,” Nebogipfel said. “Are you warm? Do you feel comfortable?”

As I have noted, my apparent exposure to the wastes of White Earth, sheltered only by this invisible dome of the Constructors, had left me feeling chilled; but I knew this could only be an internal reaction. “I’m quite satisfactory.”

“Of course. So am I. And — since we have now been traveling perhaps a quarter-hour — we know that equable conditions have persisted in this building for more than half a million years.”

“But,” I said, following his thinking, “this tower of ours is just as prone to the predations of time as any other… therefore our Constructor must be repairing the place, continually, to allow it to continue to serve us.”

“Yes. Otherwise this dome which shelters us would surely have splintered and fallen away a long time ago.”

Nebogipfel was right, of course — it was another facet of the extraordinary steadiness of purpose of the Constructors — but it scarcely made me feel more comfortable! I glanced about, studying the floor beneath us; I felt as if the tower had become as insubstantial as a termite hill, being endlessly burrowed through and rebuilt by the Universal Constructors, and I was filled with vertigo!

Now I became aware of a change in the quality of light. The glaciated landscape stretched around us, apparently unchanged; but it seemed to me that the ice was rather more darkly lit than before.

The bands of sun and moon, rendered diffuse and indistinct by their precessional motions, still rocked through the sky; but — though the moon still seemed to be shining with the violent green of its transplanted vegetation — the sun appeared to be undergoing a cycle of change.