It was as if I hung, alone, in all that immensity. If the Constructors were there, I had no sense of them. My feeling for the passage of time loosened and fell away; I could not tell if I was witnessing events on the scale of centuries or seconds, or if I was watching the evolution of stars or atoms. Before entering this last soup of light I had retained a residual sense of place — I had kept a feeling of up and down — of near and far… The world around me had been structured like a great room, within which I was suspended. But now, in this Epoch of Last Scattering, all of that fell away from me. I was a mote of awareness, bobbing about on the surface of that great River which was winding back to its source all about me, and I could only allow that ultimate stream to carry me where it would.

The soup of radiation became hotter — it was unbearably intense — and I saw that the matter of the universe, the matter which would one day compose the stars, planets and my own abandoned body, was but a thin trace of solidity, a contaminant in that seething maelstrom of light and stars. At last — I seemed to be able to see it — even the cores of atoms fizzed apart, under the pressure of that unbearable light. Space was filled with a soup of still more elemental particles, which combined and recombined in a sort of complex, microscopic melee, all about me.

We are close to the Boundary, Nebogipfel whispered. The beginning of time itself… and yet you must imagine that we are not alone: that our History — this young, glowing universe — is but one of an infinite number which has emerged from that Boundary; and that as we retreat all the members of that Multiplicity are converging towards this moment, this Boundary, like swooping birds…

But still the contraction of it all continued — still the temperature climbed, still the density of matter and energy grew; and now even those final fragments of radiation and matter were absorbed back into the shearing carcass of Space and Time, their energies stored in the stress of that great Twisting.

Until, in the end…

The last, sparkling particles fell away from me softly, and the glare of radiation heightened to a sort of invisibility.

Now, only a gray-white light filled my awareness: but that is a metaphor, for I knew that what I was experiencing now was not the light of Physics, but that glow hypothesized by Plato, the light which underlies all awareness — the light against which matter, events and minds are mere shadows.

We have reached the Nucleation, whispered Nebogipfel. Space and Time are so twisted over that they are indistinguishable. There is no Physics here… There is no Structure. One cannot point and say: that is there, such a distance away; and I am here. There is no Measurement — no Observation… It is all as One.

And, just as our History has shriveled to a single, searing point, so the Multiplicity of Histories has converged. The Boundary itself is melting away — can you understand it? — lost in the infinite possibilities of the collapsed Multiplicity…

And then there was a single, very brilliant, pulse of light: of Plattnerite green.

The merged Multiplicity convulsed. I felt twisted about — stretched and battered — as if the great River of causality which bore me had grown turbulent and hostile.

Nebogipfel?…

His voice was joyful — exultant. It is the Constructors! The Constructors…

The buffeting faded. The green glow fell away, leaving me immersed again in the gray-white of that moment of Creation. Then a new, plain white light emerged, but that persisted for only a moment; and then I watched as energy and matter condensed like dew out of a new unraveling of Space and Time.

I was traveling forward in time once more, away from the Boundary. I had been pitched into a new History, unfolding out of the Nucleation. The universal glare remained brilliant, surely still many orders of magnitude brighter than the center of the sun.

The Time Ships no longer accompanied me — perhaps their physical forms had been unable to survive that journey through the Nucleation — and the Plattnerite netting around me had gone. But I was not alone; all about me — like snowflakes caught in a flash-lamp’s burst — were speckles of Plattnerite-green light, which bobbed and drifted about each other. These were the elemental consciousness of the Constructors, I knew, and I wondered if Nebogipfel was among this disembodied host, and indeed if I, too, appeared to the rest as a dancing point.

Had my journey through time been reversed? Was I to swim up the streams of History, to my own era once more?

… Nebogipfel? Can you still hear me?

I am here.

What is happening? Are we traveling through time again?

No, he said. Still he had that note of exultation — of triumph — in his disembodied voice.

Then what? What is happening to us?

Do you not see? Could you not understand? We passed beyond the Nucleation. We reached the Boundary. And —

Yes?

Think of the Multiplicity as a surface, he said. The totality of the Multiplicity is smooth, closed, featureless — a globe. And Histories are like lines of longitude, drawn between the poles of the sphere…

And, in the Time Ships, we reached one pole.

Yes. That point where all the longitude lines converge. And, in that precise instant of infinite possibility, the Constructors fired their Nonlinearity Engines…

The Constructors have traveled across the Histories, he said. They — and we — have followed paths of Imaginary Time, paths scrawled sideways across the surface of the Multiplicity globe, until we have reached this new History…

Now the cloud of Constructors — there were millions of them, I thought — drifted apart, like fragments of a child’s firework. It was as if they were trying to fill up the infant vacuum with the light and awareness we had brought from a different cosmos. And as the new universe unraveled, the afterglow of Creation faded to an immense darkness.

It was the end-result — the logical conclusion — of my own dabbling with the properties of light, and the distortion of the frames of Space and Time that went with it. All of this, I realized, even the collapsing of the universe and this great progression across Histories — all of it had come about, growing inevitably, from my experiments, from my first, dear machine of brass and quartz…

It had led to this: the passage of Mind between universes.

But where have we come to? What is this History? Is it like ours?

No, Nebogipfel said. No, it is not like ours.

Will we be able to live here?

I do not know… it was not chosen for us. Remember that the Constructors have sought, he said, a universe — out of all the in finite sheaf of possibilities that is the Multiplicity — a universe which is optimal for them.

Yes. But what can “optimal “mean for a Constructor? I conjured up vague images of Heaven — of peace, security, beauty, light — but I knew these imaginings were hopelessly anthropomorphic.

Now I saw a new light emerging, from the darkness all around us. At first I thought it was the returned glow of that fireball at the beginning of time — but it was too gentle, too insistent, for that; it was more like star-light…

The Constructors are not men, the Morlock said. But they are the Heirs of Humanity. And the audacity of what they have accomplished is astonishing.

Nebogipfel said, Among all the myriad possibilities, the Constructors have sought out that universe — the single one — which is Infinite in extent, and Eternal in age: where that Boundary at the Beginning of Time has been pushed into the infinite past.