The man I searched for could be anybody at all.
If I didn't find him, there'd be nobody at all.

One more city. The pattern went on. One more city to search for a man I did not know, whose face I would not recognize. I had no copy of either his fingerprints or encephalograph, or any other clue to his identity.

Yet he had to be found.

At one time he had been my best friend. His name was Howard Zealley then. He wouldn't be using the same name now.

And the "bug" in his brain would by this time have made him a stranger.

There was only one way the job could be done: I had to make contact—even though I might not be aware of it at the time—reveal who I was, and hope he'd come out after me.

I rented a room in a cheap hotel. But not so cheap that it wouldn't have a grid connection with information service.

I wrote my name big on the register: MAX CALOF. There was always the chance that he would see it. He would remember the name.

The room was small, a standard "living-in" cubicle. Which was all right. I didn't intend to sleep here. I hadn't slept in nine years now—a year before the chase began. I kicked off my saddle shoes and walked on stockinged feet to the vid coin slot and dropped in a half dollar.

The screen flickered once and the face of a beautiful, smiling woman came into focus. "May I help you, sir?" she asked in a pleasant, very friendly voice.

I realized that the woman was not actually speaking, as she appeared to be doing. She was merely a woman image, with her voice and facial expressions synchronized in some way with the word impulses coming from information central.

I stretched out on the bed, folding the pillow under my head to have an unobstructed view of the screen. "Give me the names of the city's two hundred most prominent male citizens," I said.

There was no sign of surprise on the woman face, but I got the usual expressive long pause from central. The request was unusual. Central relays always had trouble with the proper definition of "prominent."

"Any particular category?" the woman image finally asked.

"All categories," I answered.

Another pause. Even a mechanical brain would take a bit of time to assemble that information, but get it I would.

After a while the woman began. "Edward Anderson. Russell Baker. Joseph Dillon. Francis...." As her gently modulated voice went on, I closed my eyes, keeping my mind blank, letting each name pass without resistance through my consciousness. Sometimes a hunch came that way. There was no need to make a written list. I had total recall.

I became aware that I had opened my shirt collar and that I was perspiring. I hadn't noticed how hot the day was or that the room had no air conditioning. I took a minute to concentrate. The perspiration dried and my body adjusted itself to the room's temperature and humidity. When I was comfortable again, I returned my attention to the woman's voice.

At the end of the reading, no name had stayed with me. I opened my eyes. "Eliminate all except those within the age range of twenty to forty," I said. Zealley would be thirty-seven by now—but probably appear younger. "Got that?"

"Yes sir."

"How many left?" I asked.

"Sixty-four."

It was always a temptation to cut the list further. I was weary of the seemingly endless repetition of the same routine and the frustrating lack of any results. Eight years is a long time to search for a man. Yet I could not afford to be careless. I was gambling everything on my having figured out the way Zealley's mind operated, how he would act, where he would hide. When the woman finished speaking, I walked to the vid and switched it off.

I noted by the wall clock that it was almost noon. I hadn't had breakfast yet. In the back of my mind, as I ordered a meal, was the certainty that someday this appetite too would grow sated and dull. There were so few satisfactions left....

The first name on my list was Edward Anderson. The city's mayor. It took me two hours to get into his office, and two minutes to be on my way out again. I had asked my questions and met the usual blank response.

On the street I spent another hour strolling through the shopping district. No shadower picked me up.

Which pretty well eliminated Anderson—or anyone in close contact with him.

Second name, Russell Baker. Industrialist. Minneapolis Mining & Allied Products.

I got as far as his secretary, John Roesler.

"What can I do for you?" Roesler asked. He was a big-boned, handsome man, with an air of sleepy indolence. He cleaned and trimmed his fingernails with a small gold penknife.

"I'd like to see Mr. Baker," I said.

"What about?"

"Confidential business."

"No one gets in to see a man like Mr. Baker that easy. If they could, he'd be pestered by every crackpot in town."

This was as far as I was going to get. I had to make the best of it. "Will you give him a message then?" I asked.

Roesler shrugged. "If I think he should have it."

"I would advise you to deliver it," I said making my tone as impressive as possible. "If he doesn't get it, you may be out of a job."

His eyebrows raised slightly.

"Tell him," I said, "that Max Calof wants to see him," and spelled my last name for him.

"And what should I say you want to see him about?" I had caught a slight break in Roesler's composure.

"About a mutual friend—Howard Zealley," I replied. "I think he'll be interested."

Roesler hid a yawn behind a well-manicured hand. "We'll see," he said, and I went back out.

Twice within ten minutes I observed the same pale-faced youth trailing me, and my pulse gave a great racing bound. This could be it.

I stopped and studied the men's hats in a shop window. From the side of my eye I saw the youth stop also. He leaned against a traffic light stanchion and kicked idly at a scrap of paper on the sidewalk.

I wandered through a department store, stopping to purchase a toothbrush and a handkerchief, and he followed, keeping always a discreet distance behind. My last doubt was removed. I returned to my hotel. With luck, the hunter would now become the hunted.

In my room I pulled a grip from under the bed and took out a rubber-handled screwdriver and a pair of pliers, a pocket knife, several lengths of copper wire, and a small instrument in a black case about the size of my fist. Climbing on a straight-back chair, I removed the frosted globe from the room's center light. I bared the wires, carefully spliced on two pieces of wire, connected the black box, and replaced the globe.

I had a little more trouble with the electrical clock's wiring, but at the end I was satisfied. The time was two-fifteen. I made my setting for three o'clock. Zealley should be here before then. If not, I could always set the timing back.

There was nothing to do now except wait.

Nearly a half hour passed from the time I finished my preparations, and I was beginning to think Zealley would be late, when the door of my compartment was kicked savagely open.

The man who followed the kick was lean and dark, with wavy brown hair combed meticulously into place. A bent nose dispelled any illusion of softness.

I was disappointed. If this was Zealley, it was not at all the way I had expected him to look. I had thought he would be more polished perhaps, more intelligent, with more of the outward signs of success.

This weighing I did with a fleeting glance, and passed to the two men who followed my first visitor: Roesler and the pale-faced youth. Roesler was wearing a yellow hat.

I swung my legs over the side of the bed where I had been lying and sat up. "Come in," I said.

The sarcasm was not wasted on Roesler. He kept his gaze on me, but spoke to the two men with him. "Stay by the door, George," he ordered the boy. "You, Steve," he addressed the lean man, "get on the other side of him. Stay close." He let himself ease into the lounge chair behind him.

I decided to stir things up a bit. "I see you brought a boy," I said, nodding at the one by the door. "This might turn out to be a man's job."

Roesler glanced aside at the youth, whose lips pulled away from his teeth and eyes filled with quick hate. He pulled a switch-blade knife from his pocket and snapped it open.

I found myself making a swift reappraisal. The lad was not the simple hood type I had first judged him to be. There was a flat look about the wide whites of his eyes that warned of something apart from courage.

"Not yet, George," Roesler said, and his voice, though almost gentle, stopped the boy before he took a step.

Roesler pulled his penknife from a coat pocket and began trimming his nails.

"Someday you're going to run out of fingernails," I said.

Roesler laughed soundlessly, amused.

I glanced unobtrusively at the clock. Ten minutes to three. Time passed slowly in a situation like this.

Roesler regarded me speculatively. "You don't seem very nervous," he said.

"Should I be?"

"I would think so," he said. "If I were in your position, I think I'd be nervous."

"Would you?"

"Take off your clothes," he said, with no change of tone.

I took in a long breath and began opening my shirt. Another glance at the clock told me I needed at least eight more minutes. I had to stall.

Roesler made no attempt to hurry me. He was a man certain of his control of the situation.

I kicked off my shorts, the last of my clothes, and for the first time felt ill at ease. Standing stripped to the raw before these men put me at a mental disadvantage. I feared them only to the point of discretion, but I had lost a bit of my poise. I sat back on the edge of the bed and lit a cigarette, doing my best to appear unconcerned.

Roesler turned to the dark man. "The shade, Steve," he directed. "Pull it down a minute."

Steve did as he was told.

The fact that my skin glowed with a faint phosphorescent sheen in the semidarkness was no surprise to me.

Roesler leaned forward and the penknife, which he had set on one knee, slipped off. Without attention he caught it before it touched the floor.

Which confirmed my original suspicion. No one had reflexes that fast—except Zealley—and myself. I had estimated him correctly then. He had been too clever to expose himself to any searcher; he had disdained the prestige he might have acquired, staying in the background, but in a position where he could observe any pursuer if and when he appeared.

Roesler-Zealley had noted the brief play of understanding on my face and he nodded. "I had to be certain, Max," he said. "You've changed too, you know."

Which was true. The mites in our veins had altered us both considerably through the years. We had developed some small empathy with them and they often performed as we wished. It was not that they could read our thoughts. Their activities were probably only reactions to our emotional and glandular functions. Moreover, they acted as often in ways that suited their own designs, changing our body structures, and regulating our metabolisms, seemingly at random.

"What did you want with me, Max?" Zealley asked, still being very pleasant. "Did you come to join me in conquering the world?"

He was being facetious and I did not answer him. He knew why I was here.

Overhead a faint click came from the light globe, a sound that probably only I noticed, and I knew that my alarm had gone off. I judged it would take the police only a few minutes to reach here.

"Or are you going to pretend that the medics have found a way to boil the bugs out of us?" Zealley asked. Did I detect a concealed pleading for just that assurance?

I shook my head. "No, they haven't found any way, Howard," I obliterated the hope.

"Good old Max." Bitterness crept into his voice. "Faithful, selfless old Max. Going to save the world. Going to save the whole of humanity," he amended expansively.

He hadn't changed too much. Sarcasm had always come natural with him, which made it no more likable.

He might have said dull, stupid, cloddish old Max. The words would have better matched the tone of his voice. At that, he might be right. The authorities back on our home world of New Nebraska had said pretty much the same thing, only more diplomatically.

"You and Zealley are different," I'd been told. "That was one of the reasons we made you a team, originally. Zealley is clever and imaginative, but basically an egotist. A to-hell-with-the-other-fellow character. Fortunately, you're not like him. You're a man who accepts his responsibilities, a man with a strong sense of duty. We know we can trust you." Whether it was actually trust or only that they had little choice, I had not let myself decide.

"We had such high hopes." Zealley was reminiscing, speaking more to himself than to me.

We had. We'd been a two-man survey crew, mapping out new territory for the future expansion of the human race. On a world listed only as TR768-L-14 on the star maps, we had run into disaster. We found the planet unfit for human habitation, but not before we'd been bitten several times by things we never did see.

No infection had resulted and we thought little about it, until we were a good part of the way home. Gradually then we noticed a quickening of our sensory processes, a well-being of body too pronounced to be normal. During the next several weeks of flight, Zealley wrote a historical novel that I was certain would turn out to be a classic. I found myself mastering, without difficulty, higher math, which had always been beyond me before.

At the end of the third month we stopped needing sleep. During the days and nights that followed we conversed brilliantly on subjects that had not interested us before, and the depth of which we couldn't have fathomed if they had interested us. We were at a loss to explain the reason for the change, though we knew it tied in somehow with our stay on TR768-L-14, and probably with the things that had bitten us. The cause was of secondary importance; the marvel of the reality was what intrigued us. We looked forward with poorly restrained excitement to displaying our new mental and physical dexterity.

The Space Bureau authorities were every bit as impressed as we had anticipated. The medics readily found that we had been infested by a germ, but by a benevolent germ, a true symbiote. That discovery was followed by months of tests and examinations.

Between sessions with our own medics and laboratory men and various visiting specialists, we amused ourselves by showing our new abilities. At least a dozen times a day I had to put someone down in an arm wrestle. Even when they devised a way to pit two against me at a time, I had little difficulty besting them.

Zealley's displays tended toward the more flamboyant. One of the tricks he delighted in was taking a razor blade, and, while his audience watched with repelled fascination, cut a long gash in his forearm. For an instant the blood would ebb out, then quickly clot and cease to flow. The next day he would show them the arm, where a thin red line at the most would remain to mark where the wound had been.

Apparently Zealley's reminiscing had kept pace with my own. "It seems such a shame, doesn't it, Max?" he asked. He was genuinely sad.

So was I.

Test results and theories developed fast in those early days. The findings showed that the symbiotes repaired damage and faults in our systems and protected us against disease. It was even hazarded that they would prolong our lives indefinitely.

Yet we were warned against complacency. The bug—we always spoke of it in the singular, even though we knew the original mites had spawned in our blood streams—could not act quickly enough to save our lives in the event of major damage to essential organs or the brain. Also, we could drown. Or we could die in a fall from a great height. Or starve to death.

The first intimation we had that all was not well had started as a rumor. Two of the staff biochemists had been experimenting with transplants of the bugs in fruit flies. They had turned up something sensational.

Zealley was not present when I received the disastrous news. At the end of what would normally be a twenty- or thirty-year cycle—the chemists were not able to estimate it any closer—the symbiotes evolved into tiny winged insects.

At that stage they acquired size and flying strength by devouring the tissues of their hosts.