"But why? Why do you want to..."

He silenced me with a stare. "If Ormazd has not told you, why should I?"

I tried to see past his words, but my mind struck an utterly implacable wall.

"I will tell you this much," Ahriman whispered.

"This fusion reactor of yours is a nexus point in your race's development. If you make the fusion process work, you will be expanding out to the stars within a generation. I will not allow you to accomplish that I will not allow you to accomplish that."

"I don't understand."

"How could you?" He leaned closer to me, and I could smell the odor of ashes and death upon him. "This fusion machine, this CTR as you call it, is the key to your race's future. If it is successful, fusion will supply limitless energy for you. Wealth and plenty for all. Your people could stop playing with their puny chemical rockets and start building real starships. They could expand throughout the galaxy."

"They have have done so," I realized. done so," I realized.

"Yes they have. But if I can change the nexus here, at this point in time, if I can destroy that fusion reactor..." He smiled again. And I shuddered.

I tried to pull myself together. "The failure of one machine can't kill the entire human race."

"Yes, it can, thanks to the maniac nature of your kind. When the fusion reactor explodes..."

"It can't explode!" I snapped.

"Of course not. Not under ordinary circumstances. But I have access to extraordinary means. I can create a sudden surge of power from the lasers. I can cause a detonation of the lithium shielding that surrounds the reactor's ignition chamber. Instead of a microgram of deuterium being fused and giving off a puff of energy, a quarter ton of lithium and heavier metals will explode."

"They can't..."

"Instead of a tiny, controlled, man-made star radiating energy in a controlled flow, I will create an artificial supernova, a lithium bomb. The explosion will destroy Ann Arbor totally. The fallout will kill millions of people from Detroit to New York."

I sagged back, stunned.

"Even if your leaders are wise enough to recognize that this is an accident and not a nuclear attack, even if they refrain from launching their missiles at their enemies, your people will react violently against fusion power. Their earlier protests which closed all the uranium fission power plants will seem like child's play compared to their reaction to this disaster. There will be an end to all nuclear research everywhere. You will never get fusion power. Never."

"Even so, we will survive."

"Will you? I have all the time in the world to work with. I can be patient. As the years go by, your growing population will demand more and more energy. Your mighty nations will struggle against each other for possession of petroleum, coal, food resources. There will be war, inevitably. And for war, you have fusion devices that do work-H-bombs."

"Armageddon," I said.

He nodded that massive head in triumph. "At the time when you should be expanding outward toward the stars, you will destroy yourselves with nuclear war. This planet will be scoured clean of life. The fabric of space-time itself will be so ruptured that the entire continuum will collapse and die. Armageddon, indeed."

I wanted to stop him, to silence him. I wanted to kill him just as he had killed Aretha. I leaped for his throat, snarling. He was real, no hologram. And he was incredibly strong. He brushed me aside easily, knocking me to the floor as if I were a child.

Standing over me like the dark force of doom, he said in his harsh, whispering voice, "Despite what Ormazd has told you, I will succeed in this. You will die, Orion. Here. You are trapped in this chamber, while I shall destroy your fusion machine."

"But why?" I asked, climbing slowly back to the couch. "Why do you want to wipe out the human race?"

He stood for a moment, glaring at me with those burning eyes. "You really don't know, do you? He never told you... or he erased your memory of it."

"I don't know," I said. "Why do you hate the human race?"

"Because you wiped out my my race," Ahriman answered, his harsh voice nearly strangling on the words. "Millennia ago, your people killed mine. You annihilated my entire species. I am the only one of my kind left alive, and I will avenge my race by destroying yours-and your masters as well." race," Ahriman answered, his harsh voice nearly strangling on the words. "Millennia ago, your people killed mine. You annihilated my entire species. I am the only one of my kind left alive, and I will avenge my race by destroying yours-and your masters as well."

The strength left me. I sat weakly on the couch, unable to challenge him, unable to move.

"And now, good-bye," Ahriman said. "I have work to do before the first test run of your fusion reactor. You will remain here...." He gestured around the tiny room. It had no doors or windows. No exits or entrances of any kind. How did we get in here? How did we get in here? I wondered. I wondered.

"If I succeed, it will all be over in a few hours," Ahriman said. "Time itself will begin to falter and the universe will fall in on itself like a collapsing balloon. If I fail, well..." that ghastly smile again, "...you will never know it. This chamber will be your tomb. Or, more properly, your crematorium."

"Where are we?" I asked.

"Thirty miles underground, in a temporary bubble of safety and comfort created by warping the energies of the atoms around us. Think about that as you burn-you are only a step away from the house in Ann Arbor. One small step for a man, if he truly understands the way the universe is constructed." He turned abruptly and walked through through the wall and disappeared. the wall and disappeared.

CHAPTER 7.

For long minutes I sat on the couch unmoving, my body numb with shock, my mind spinning in turmoil.

You wiped out my race... your people killed mine... and I will avenge my race by destroying yours-and your masters as well.

It couldn't be true. And what did he mean by his talk of the two of us moving on different time tracks, of having met before? Your masters? What did he mean by that? Ormazd? But he said masters, plural. Is Ormazd the representative of a different race, an alien race from another world that controls all of humankind? Just as Ahriman is the last survivor of an alien race that we humans battled so long ago?

How many times had we met before? Ahriman said that this point in time, this first test of the fusion reactor, marked a nexus tor the human race. If it succeeds, we will use fusion energy to reach out to the stars. If it fails, we will kill ourselves within a generation. There must have been other nexuses back through time, many of them.

Somewhere back along those eons there was a war, The War, between the human race and Ahriman's kind. When? Why? How could we fight invaders from another world back in the past, thousands of years ago?

All these thoughts were bubbling through my brain until finally my body asserted itself on my conscious awareness.

"It's getting hot in here," I said aloud.

My attention snapped to the present. To this tiny cell. The air was hot and dry. My throat felt raw. The room was now hot enough to make me sweat.

I got up and felt the nearest wall. It was almost too hot to touch. And although it looked like wood paneling, it felt like stone. It was an illusion, all of it.

One small step for a man... if he truly understands the way the universe is constructed.

I understood nothing. I could remember nothing. All I could think of was that Ahriman was back on Earth's surface, up in Ann Arbor, working to turn the CTR into a mammoth lithium bomb that would trigger the destruction of the human race. And I was trapped here, thirty miles underground, about to be roasted like a sacrificial lamb on a spit.

You are only a step away from the house in Ann Arbor, he had said. Was that a lie? A joke? His idea of a cruel taunt?

"One small step for a man," I muttered to myself. How is is the universe constructed? It's made of atoms. And atoms are made of smaller particles, tiny bits of frozen energy that can be made to thaw and flow and surge... the universe constructed? It's made of atoms. And atoms are made of smaller particles, tiny bits of frozen energy that can be made to thaw and flow and surge...

This room had been created by warping the energies of the atoms in the Earth's crust. Those energies were now reverting back to their natural form; slowly the room was turning back into hot, viscous rock. I could feel the air congealing, becoming hotter and thicker by the second. I would be imbedded in rock thirty miles below the surface, rock hot enough to be almost molten.

Yet I was only a step from safety, according to Ahriman. Was he lying? No, he couldn't have been. He He had walked directly through the rock wall of this room. He must have returned to the cellar of the house in Ann Arbor. If he could do it, so could I. But how? had walked directly through the rock wall of this room. He must have returned to the cellar of the house in Ann Arbor. If he could do it, so could I. But how?

I already had! I had stepped from the cellar into this underground dungeon. Why couldn't I step back again? I had stepped from the cellar into this underground dungeon. Why couldn't I step back again?

I tried doing it and got nothing but bumps against solid rock for my efforts. There was more to it than simply trying it.

But wait. If I had truly traveled thirty miles through solid rock in a single step, it must mean that there is a connection between that house and this chamber. Not only are the atoms of Earth's crust being warped to create this cell, but the geometry of space itself is being warped to bridge the thirty-mile distance.

I sat on the couch again, my mind racing. I had read magazine articles about space warps, speculations about how someday starships would be able to fly thousands of lightyears almost instantaneously. Astrophysicists had discovered "black holes" in interstellar space that warped space-time with their titanic gravitational fields. It was all a matter of geometry, a pattern, like taking a flat sheet of paper and folding it into the form of a bird or a flower.

And I had seen that pattern! I had gone through it on my way into this chamber. But it had happened so quickly that I could not consciously remember it in detail.

Or could I?

Data compression. Satellites in orbit can accumulate data on magnetic tapes for days on end, and then spurt it all down to a receiving station on the ground within a few seconds. The compressed data is then played at a much slower speed by the technicians, and all the many days' worth of information is intact and readable.

Could I slow down my memory to the point where I could recall, miscrosecond by microsecond, what had happened to me during that one brief stride from the house to this underground tomb? I leaned back on the couch and closed my eyes. It was getting more and more difficult to breathe, but I tried to ignore the burning in my chest and concentrate on remembering.

A thirty-mile stride. A step through solid rock. I pictured myself in the cellar of that house. I had ducked under a heating pipe and stepped into darkness....

And cold. The first instant of my step I had felt a wave of intense cold, as if I had passed through a curtain of liquefied air. Cryogenic cold. Cold so intense that atoms are frozen almost motionless, at nearly absolute zero temperature.

In those few microseconds of unbearable cold I saw that the crystal structure of the atoms around me had indeed been frozen, almost entirely stilled. All around me the atoms glowed dully like pinpoints of jeweled lights, faint and sullen because nearly all their energies had been leached away from them. The crystal latticework of the atoms had formed a path for me, a tunnel wide enough for my body to take that thirty-mile-long step in a single stride.

I opened my eyes. The tiny room was glowing now; the air itself seemed afire. I held my breath, wondering how long my body could function on the oxygen stored within its cells and in my blood.

I understood how I had gotten here. There was a crystal latticework of energy connecting this crypt with the house in Ann Arbor-a tunnel that connected here here with with there there, using the energies stolen from the atoms in between to create a safe and almost instantaneous path between the two places. But the tunnel was dissolving just as this room was dissolving. The energies of those tortured atoms was returning to normal. In seconds all would be solid rock once again.

How to find the opening into that tunnel? I concentrated again, but no sense of it came through to me. I was sweating, both from the intense heat and from the effort of forcing myself to understand. But it did no good at all. My brain could not comprehend it.

My brain could not... Wrong! Wrong! I realized that I had so far been using only half my brain to attack the problem. I remembered Ormazd telling me that I could consciously employ both hemispheres simultaneously, something that ordinary human beings cannot do. I had been using one hemisphere to visualize the geometric pattern of the energy warp that connected this underground chamber with the surface. But that half of my brain could I realized that I had so far been using only half my brain to attack the problem. I remembered Ormazd telling me that I could consciously employ both hemispheres simultaneously, something that ordinary human beings cannot do. I had been using one hemisphere to visualize the geometric pattern of the energy warp that connected this underground chamber with the surface. But that half of my brain could only only perceive geometrically those relationships involving space and form. perceive geometrically those relationships involving space and form.

With a conscious effort I forced the other hemisphere of my brain to consider the problem. I could almost hear myself laugh inside my head as the unused portion of my mind said something like, "Well, it's about time."

And it was about time. The solution to the problem of finding the gateway to the crystal latticework of atoms was a matter of timing. All those dully glowing atoms were still vibrating slowly, unnaturally slowly, because most of their energies had been drained from them. But still they vibrated. Only when they had all moved to a certain precise formation was their alignment such that the tunnel's entrance could open. Most of the time they were shifted out of phase, as unaligned and jumbled as a crowd milling through a shopping mall. But once every second they reached precisely the correct arrangement to open the tunnel that led back to safety. The arrangement dissolved within a few microseconds.

Only during that incredibly tiny moment of time was the tunnel open. I had to step into the crystal latticework, through the searing hot wall of the chamber, at precisely the exact moment-or not at all.

I got to my feet and forced myself close to the wall. The heat was enough to singe the hair of my eyebrows and the backs of my hands. I kept my eyes closed, picturing with one side of my brain the crystal pathway itself, while simultaneously calculating with the other side of my brain the precise moment when the lattice would be open for me to step through.

With my eyes still closed I took a step forward. I felt an instant of roasting heat, then cold beyond the most frigid ice fields of Antarctica. Then...

I opened my eyes. I stood in the shadowy cellar of the STOPP house. For the first time in what seemed like years, I let out my breath and took in a double lungful of sweet, cool air.

I found a back door to the cellar and stepped out into the cold night. It felt wonderful. An alley led between the house and its next-door neighbor to the street. My rented car was still there, adorned with a yellow parking ticket affixed to its windshield wiper. I stuffed the ticket into my jacket pocket and got behind the wheel, glad that no one had towed the car away or stolen it.

It took me ten minutes to get back to the fusion lab. Once in the deserted lobby of the building, I phoned for Tom Dempsey, Mangino the security chief, and the lab's director of research. It was close to midnight, but the tone of my voice must have convinced them that something important was happening. I got no arguments from any of them, although the phone's computer had to try three different numbers before it located Dr. Wilson, the research director.

They all arrived in the lab within a half-hour-thirty minutes during which I checked personally with every security guard on duty. No one had reported the slightest problem. They were on constant patrol around the laboratory, inside and out, and everything appeared to be quite normal.

Dr. Wilson was a lanky, ruddy-faced, tousle-haired Englishman who spoke softly and seemed totally unflappable. He arrived first. As I was explaining that somebody would try to detonate the fusion reactor-and he smiled tolerantly at the ridiculous idea-Dempsey and the security chief came into the lobby together. Dempsey looked more puzzled than upset. His dark hair was an uncombed, tangled mop; he must have been asleep when I called and pulled his clothes on helter-skelter. Mangino was definitely angry. His narrow brown eyes snapped at me.

"This is a lot of hysterical nonsense," he growled, when I explained my fears. I didn't tell them about Ormazd and Ahriman, of course, nor about the underground chamber I'd just escaped from. It was enough to convince them that a real danger existed. I didn't want them to bundle me off to a psychiatric ward.

Dr. Wilson tried to tell me that the reactor simply could not explode. I let him talk; the longer he explained, the longer we stayed on the scene, available to counter Ahriman's move.

"There simply is not enough deuterium in the reactor at any given moment to allow an explosion," Wilson repeated in a his soft, friendly voice. He sat slouched on one of the plastic couches that decorated the lab's lobby. I stood by the receptionist's desk. Dempsey had stretched out on another couch and apparently had gone back to sleep. Mangino was behind the desk, checking out his security patrols on the picture phone.

"But suppose," I stalled for more time, "there was a way to boost the power of the lasers..."

"They'd burn out in a minute," Wilson said. "We're running them at top capacity now."

"...and an extra amount of deuterium was put into the reaction chamber."

Wilson shook his head, and a mass of sandy hair flopped down over his eyes. Pushing it back with one hand, he told me, "That simply cannot happen. There are fail-safe circuits to prevent it. And even if it did, all that would happen is that you would get a mild little poof of a detonation-not a hydrogen bomb."

"What about a lithium bomb?" I asked.

For the first time, his eyebrows knit worriedly. "What do you mean?"

"If things worked out the right way, couldn't the deuterium detonation trigger the lithium in the shielding around the reaction chamber?"

"No, no. That would be impos-" He checked himself, hesitated, then said slowly, "That would be very unlikely. Very Very unlikely. I'd have to work out the calculations, of course, but the chances against that must be..." unlikely. I'd have to work out the calculations, of course, but the chances against that must be..."

"Twenty-four, report report." Mangino's razor-sharp voice sliced into our conversation.

I turned and looked at the security chief. He was frowning angrily into the phone's picture screen. "Dammit, Twenty-four, answer me!"

He looked up at me, as if I were responsible. "One of the guards outside doesn't respond. He's supposed to be patrolling the area around the loading dock."

"The loading dock!" Wilson shot to his feet. I could see that he had started to tremble.

Mangino held up a hand. "Don't get excited, now. I've got the area on one of the outside TV cameras. Everything looks normal. Just no sign of the guard. He might be taking a leak or something."

I went around the desk and peered at the TV screen. The loading bay was brightly lit. There were no cars or trucks anywhere in sight. All seemed quiet and calm.

"Let's take a walk down there anyway," I said.

We roused Dempsey and told him to stand guard over the phones and TV screens. He rubbed his eyes sleepily but nodded okay. Then Dr. Wilson, Mangino and I hurried down the building's central corridor toward the loading dock. Mangino reached inside his coat and pulled out a slim, flat, dead-black pistol. He flicked the safety off and then slipped it into his jacket pocket.

Lights turned on automatically ahead of us as we hustled along the corridor, and switched off behind us. The loading bay was a miniature warehouse: stacks of cardboard cartons, steel drums, packing cases, strange-looking equipment wrapped in clear plastic.

"You could hide a platoon of men in here," Mangino grumbled.

"But everything seems to be in order," Wilson said, glancing around. I started to agree, but felt the slightest trace of a breeze on my face. It came from the direction of the loading dock doors, big metal roll-up doors that were closed and locked tight. Or were they? I walked slowly toward the hangar-like doors and saw that a man-sized doorway had been cut into one of them. A person could slip in or out without needing to raise the entire rig. This smaller door was windowless. And shut. I reached for its handle.

"It's locked," Mangino said. "Electronic time lock. If anybody tries to tamper with it..."

I touched the handle and the door swung open effortlessly. Mangino gaped.