I knew then what the interview was all about. He was probing, trying to a.s.sess the tiger he had by the tail. Trying to discover where the power lay.

"Not this time," I said. "Not any time, really."

"Nonetheless-you"re here," he said flatly.

"Use your head," I said. "Your operation"s been based on the proposition that your era, being later, can see pitfalls the Nexx people couldn"t. Doesn"t it follow that a later era can see your mistakes?"

"We are making no mistakes."

"If you weren"t, I wouldn"t be here."

"Impossible!" he said, as if he believed it-or as if he wanted awfully badly to believe it. "For seventeen thousand years a process of disintegration has proceeded, abetted by every effort to undo it. When man first interfered with the orderly flow of time, he sowed the seeds of eventual chaos. By breaking open the entropic channel, he allowed the incalculable forces of temporal progression to diffuse across an infinite spectrum of progressively weaker matrices. Life is a product of time. When the density of the temporal flux falls below a critical value, life ends. Our intention is to prevent that ultimate tragedy-only that, and no more! We cannot fail!"

"You can"t rebuild a past that never was," I said, "or preserve a future that won"t happen."

"That is not our objective. Ours is a broad program of reknitting the temporal fabric by bringing together previously divergent trends; by grafting wild shoots back into the mainstem of time. We are apolitical; we support no ideology. We are content to preserve the vitality of the continuum."

"And of yourselves," I said.

He looked at me strangely, as if lost.

"Have you ever considered a solution that eliminated you and all your works from existence?" I asked him.

"Why should I?"

"You"re one of the results of all this time-meddling you"re dead set on correcting," I pointed out. "But I doubt if you"d entertain the idea of any timegraft that would wither your own particular branch of the tree."

"Why should I? That would be self-defeating. How can we police the continuum if we don"t exist?"

"A good question," I said.

"I have one other," he said in the tone of a man who has just settled an argument with a telling point. "What motivation could your era have for working to destroy the reality core on which any conceivable future must depend?"

I felt like sighing, but I didn"t. I got my man-to-man look into position and said, "The first Time-sweepers set out to undo the mistakes of the past. Those who came after them found themselves faced with a bigger job: cleaning up after the cleaners-up. Nexx Central tried to take the broad view, to put it all back, good and bad, where it was before the meddling started. Now you"re even more ambitious. You"re using Nexx Central to manipulate not the past, but the future-"

"Operations in future time are an impossibility," he said flatly, like Moses laying down the laws.

"Uh-huh. But to you, the Fifth Era isn"t future, remember? That gives you the edge. But you should have been smarter than that. If you can kibitz the past, what"s to keep your future from kibitzing you?"

"Are you attempting to tell me that any effort to undo the damage, to reverse the trend toward dissolution, is doomed?"

"As long as any man tries to put a harness on his own destiny, he"ll defeat himself. Every petty dictator who ever tried to enforce a total state discovered that, in his own small way. The secret of man is his unchainability. His existence depends on uncertainty, insecurity: the chance factor. Take that away and you take all."

"This is a doctrine of failure and defeat," he said flatly. "A dangerous doctrine. I intend to fight it with every resource at my command. It will now be necessary for you to inform me fully as to your princ.i.p.als: who sent you here, who directs your actions, where your base of operations is located. Everything."

"I don"t think so."

He made a swift move and I felt a sort of zinging in the air. Or in a medium less palpable than air. When he spoke again, his voice had taken on a flat, unresonant quality.

"You feel very secure, Agent. You, you tell yourself, represent a more advanced era, and are thus the immeasurable superior of any more primitive power. But a muscular fool may chain a genius. I have trapped you here. We are now safely enclosed in an achronic enclave of zero temporal dimensions, totally divorced from any conceivable outside influence. You will find that you are effectively immobilized; any suicide equipment you may possess is useless, as is any temporal transfer device. And even were you to die, your brain will be instantly tapped and drained of all knowledge, both at conscious and subconscious levels."

"You"re quite thorough," I said, "but not quite thorough enough. You covered yourself from the outside-but not from the inside."

He frowned; he didn"t like that remark. He sat up straighter in his chair and made a curt gesture to the gunhandlers on either side of me. I knew his next words would be the kill order. Before he could say them, I triggered the thought-code that had been waiting under multiple levels of deep hypnosis for this moment. He froze just like that, with his mouth open and a look of deep bewilderment in his eyes.

38.

The eclipse-like light of null-time stasis shone on his taut face, on the faces of the two armed men standing rigid with their fingers already tightening on their firing studs. I went between them, fighting the walking-through-syrup sensation, and out into the pa.s.sageway. The only sound was the slow, all-pervasive, metronome-like beat that some theoreticians say represents the basic frequency rate of the creation-destruction cycle of reality.

Room by room, I checked every square inch of the installation. The personnel were all in place, looking like the inhabitants of the enchanted castle where the sleeping beauty lay. I took my time going through the files and records. The Fifth Era infiltrators had done their work well. There was nothing here to give any indication of how far in the subjective future their operation was based, no clues to the extent of their penetration of Nexx Central"s sweep programs. This was data that would have been of interest, but wasn"t essential. I had accomplished phase one of my basic mission: smoking out the random factor that had been creating anomalies in the long-range time maps of the era.

Of a total of one hundred and twelve personnel in the station, four were Fifth Era transferees, a fact made obvious in the stasis condition by the distinctive aura that their abnormally high temporal potential created around them. I carried out a mind-wipe on pertinent memory sectors, and triggered them back to their loci of origin. There would be a certain amount of head-scratching and equipment re-examining when the original efforts to jump them back to their a.s.signments at Nexx Central apparently failed; but as far as temporal operations were concerned, all four were permanently out of action, trapped in the same type of closed-loop phenomenon that had been used on me.

The files called for some attention, too: I carried out a tape-scan in situ, edited the records to eliminate all evidence that might lead Nexx inspectors into undesirable areas of speculation.

I was just finishing up the ch.o.r.e when I heard the sound of footsteps in the corridor outside the record center.

39.

Aside from the fact that nothing not encased in an eddy-field like the one that allowed me to operate in nulltime could move here, the intrusion wasn"t too surprising. I had been hoping for a visitor of some sort; the situation almost demanded it.

He came through the door, a tall, fine-featured, totally hairless man elegantly dressed in a scarlet suit with brocaded designs in deep purple, like mauve eels coiling through red seaweed. He gave the room one of those flick-flick glances that prints the whole picture on the brain to ten decimals in a one-microsecond gestalt, nodded to me as if I were a casual acquaintance encountered at the club.

"You are very efficient," he said. He spoke with no discernible accent, but with a rather strange rhythm to his speech, as if perhaps he were accustomed to talking a lot faster. His voice was calm, a nice musical baritone.

"Not so very," I said. "I went through considerable waste motion. There were a couple of times when I wondered who was conning whom."

"A modest disclaimer," he said, as though acknowledging a routine we had to go through. "We feel that you handled the entire matter-a rather complex one-in exemplary fashion."

"Thanks," I said. "Who"s "we"?"

"Up to this point," he went on without bothering with my question, "we approve of your actions. However, to carry your mission farther would be to risk creation of an eighth-order probability vortex. You will understand the implications of this fact."

"Maybe I do and maybe I don"t," I hedged. "Who are you? How did you get in here? This enclave is double sealed."

"I think we should deal from the outset on a basis of complete candor," the man in red said. "I know your ident.i.ty, your mission. My presence here, now, should be ample evidence of that. Which in turn should make it plain that I represent a still later era than your own-and that our judgment must override your instructions."

I grunted. "So the Seventh Era comes onstage, all set to Fix It Forever."

"To point out that we have the advantage of you-not only technically but in our view of the continuum as well-is to belabor the obvious."

"Uh-huh. But what makes you think another set of vigilantes won"t land on your tail, to fix your fixing?"

"There will be no later Timesweep," the bald man said. "Ours is the Final Intervention. Through Seventh Era efforts the temporal structure will be restored not only to stability, but will be reinforced by the refusion of an entire spectrum of redundant entropic vectors."

I nodded, rather tiredly. "I see: you"re improving on nature by grafting all the threads of unrealized history back into the Mainstem. Doesn"t it strike you that"s just the sort of well-intentioned tampering that the primitive Timesweepers set out to undo?"

"I live in an era that has already begun to reap the benefits of temporal reinforcement," he said firmly. "We exist in a state of vitality that prior eras could only dimly sense in moments of exultation. We-"

"You"re kidding yourselves. Opening up a whole new order of meddling just opens up a whole new order of problems."

"Our calculations indicate otherwise. Now-"

"Did you ever stop to think that there might be a natural evolutionary process at work here-and that you"re aborting it? That the mind of man might be developing toward a point where it will expand into new conceptual levels-and that when it does, it will need a matrix of outlying probability strata to support it? That you"re fattening yourself on the seed-grain of the far future?"

For the first time, he faltered, but only for an instant.

"Not valid," he said. "The fact that no later era has stepped in to interfere is the best evidence that ours is the final Sweep."

"Suppose a later era did step in: What form do you think their interference would take?"

He gave me a flat look. "It would certainly not take the form of a Sixth Era Agent, busily erasing data from Third and Fourth Era records."

"You"re right," I said. "It wouldn"t."

"Then what-" he started in a reasonable tone-and checked himself. An idea was beginning to get through, and he wasn"t liking it very well. "You," he said. "You"re not . . . ?"

And before I could confirm or deny, he vanished.

40.

The human mind is a pattern, nothing more. The first dim flicker of awareness in the evolving forebrain of Australopithecus carried that pattern in embryo; and down through all the ages, as the human neural engine increased in power and complexity, gained control of its environment in geometrically expanding increments, the pattern never varied.

Man clings to his self-orientation as the psychological center of the Universe. He can face any challenge within that framework, suffer any loss, endure any hardship-so long as the structure remains intact.

Without it he"s a mind adrift in a trackless infinity, lacking any scale against which to measure his aspirations, his losses, his victories.

Even when the light of his intellect shows him that the structure is itself a product of his brain; that infinity knows no scale, and eternity no duration-still he clings to his self-non-self concept, as a philosopher clings to a life he knows must end, to ideals he knows are ephemeral, to causes he knows will be forgotten.

The man in red was the product of a mighty culture, based over fifty thousand years in the future of Nexx Central, itself ten millennia advanced over the first time explorers of the Old Era. He knew, with all the awareness of a superbly trained intelligence, that the existence of a later-era operative invalidated forever his secure image of the continuum, and of his people"s role therein.

But like the ground ape scuttling to escape the leap of the great cat, his instant, instinctive response to the threat to his most cherished illusions was to go to earth.

Where he went I would have to follow.

41.

Regretfully, I stripped away layer on layer of inhibitive conditioning, feeling the impact of ascending orders of awareness descending on me like tangible rockfalls. I saw the immaculate precision of the Nexx-built chamber disintegrate in my eyes into the shabby makeshift that it was, saw the glittering complexity of the instrumentation dwindle in my sight until it appeared as no more than the crude mud images of a river tribesman, or the shiny trash in a jackdaw"s nest. I felt the multiordinal universe unfold around me, sensed the layered planet underfoot, apprehended expanding s.p.a.ce, dust-clotted, felt the sweep of suns in their orbits, knew once again the rhythm of Galactic creation and dissolution, grasped and held poised in my mind the interlocking conceptualizations of time-s.p.a.ce, past-future, is-is-not.

I focused a tiny fraction of my awareness on the ripple in the gla.s.sy surface of first-order reality, probed at it, made contact. . . .

I stood on a slope of windswept rock, amid twisted shrubs with exposed roots that clutched for support like desperate hands. The man in red stood thirty feet away. As my feet grated on the loose scatter of pebbles, he twisted toward me, wide-eyed.

"No!" he shouted into the wind and stooped, caught up the man-ape"s ancient weapon, threw it at me. The stone slowed, fell at my feet.

"Don"t make it any more difficult than it has to be," I said. He cried out-an inarticulate shout of anguish springing from the preverbal portion of his brain-and disappeared. I followed, through a blink of light and darkness. . . .

Great heat, dazzling sunlight that made me think of Dinosaur Beach, so far away, in a simpler world. There was loose, powdery dust underfoot. Far away, a line of black trees lined the horizon. Near me, the man in red, aiming a small, flat weapon. Behind him, two small, dark-bearded men in soiled djellabahs of coa.r.s.e-woven black cloth stared, making mystic motions with labor-gnarled hands.

He fired. Through a sheet of pink and green fire that showered around me without touching me I saw the terror in his eyes. He vanished.

Deep night, the clods of a frozen field, a patch of yellow light gleaming from the parchment-covered window of a rude hut. He crouched against a low wall of broken stones, hiding himself in shadow like any frightened beast.

"This is useless," I said. "You know it can have only one end."

He screamed and vanished.

A sky like the throat of a thousand tornadoes; great vivid sheets of lightning that struck down through writhing rags of black cloud, struck upward from raw, rain-lashed peaks of steaming rock. A rumble under my feet like the subterranean breaking of a tidal wave of magma.

He hovered, half insubstantial, in the air before me, a ghost of the remote future existing here in the planet"s dawn, his pale face a flickering mask of agony.

"You"ll destroy yourself," I called over the boom and shriek of the wind. "You"re far outside your operational range-"

He vanished. I followed. We stood on the high arch of a railless bridge spanning a man-made gorge ten thousand feet deep. I knew it as a city of the Fifth Era, circa A.D. 20,000.

"What do you want of me?" he howled through the bared teeth of the cornered carnivore.

"Go back," I said. "Tell them . . . as much as they must know."