by Hal Clement
“Has anyone been poking around the reef lately?” he asked.
“We haven’t,” replied Rice. “Hugh stepped through the bottom of the boat six weeks ago, and we haven’t been able to find a usable plank to fix it so far.”
“That bottom had been promissing to go for months,” Colby came sturdily to his own defense. Nobody saw fit to contradict him.
“Anyway, we have to go the long way around to the south shore now,” added Rice. “A storm in December shoved a brain coral bigger than the boat into the Gate. Dad’s been promising to dynamite it ever since, but he hasn’t got around to it yet.”
“How about the beach, then?” asked Bob. “We could walk part of the south shore, anyway—and grab a swim at the Breakers as we went around. I haven’t been in salt water since the last time we were in it together.” Expressions of agreement came from the others, and they dispersed to collect the bicycles which were leaning against the school building.
Conversation, in which the Hunter took deep interest, was continued without interruption as the group wheeled rapidly up the road toward the island’s tip. As he listened, he also watched through Bob’s eyes, absorbing as much as possible of the local geography. A couple of hundred yards from the school, the road crossed on a well-made wooden bridge a creek that carried a trickle of water from the ridge on their left down to the lagoon. A mile further on, a second, somewhat larger water-course was led under the road through a concrete culvert; the Hunter gathered from the remarks of the boys that the boat to which they had referred was kept beached at the mouth of this creek.
There was about a mile more of road to be traversed; the homes of all five of the boys were located along this stretch, at various distances up the hillside from the road. At each drive the cavalcade stopped while one of its members went uphill for his bathing suit; at the home of Norman Hay, at the very end of the hard surface, the bicycles were left and the group headed westward on foot.
Half a mile of this, partly along a trail through the almost junglelike growth of the ridge and partly through a relatively open grove of coconut palms, brought them to the beach; and the Hunter felt like one who has completed an Odyssey. He recognized the spot—the breakers, the sandy stretch of beach bordered by coconut palms, the scores of details that make every place in the Universe just a trifle different from, every other place. It was here he had encountered the boys swimming, when he had first emerged from Earth’s ocean onto dry land; here he had succeeded in finding his way into Bob’s body; from here his search for the creature responsible for his journey should have started; and—from here, without further delay, it would start.
He was led from a consideration of this grim resolve by more immediate questions. The boys had wasted little time changing into swimming costume; and Bob was dashing toward the surf ahead of the rest. The beach, though largely composed of fine sand, contained many pieces of sharp coral; and the boy in his haste encountered several of these before he could bring himself to a stop. The Hunter was doing his duty, so Bob’s examination of the soles of his feet produced no evidence of actual damage. Consequently he formed the conclusion that his feet had been softened by a few months in shoes, and promptly resumed his dash to the water in order to keep ahead of his companions. The Hunter was distinctly annoyed by this, and administered the twinges he had been accustomed to give his original host as warning that he was doing himself injury. Bob did not even feel the signal, and would not have known its meaning in any case; he churned into the water until he was hip-deep and plunged headlong into an incoming breaker, the others at his heels. The Hunter gave up his attempts at signaling, held the cuts closed, and seethed quietly. His presence, after all, should not be construed as license to exceed the normal safety limits of stress for his host’s body; if Bob was going to ignore possible sources of minor personal injury just because the Hunter was present and could be counted on for protection, then the alien was going to have to take some definite steps. He recalled vaguely from his historical readings that his race had had some such difficulty with the Allanese during the first few generations of symbiosis.
The swim was short; this beach was the only part of the island unprotected by the reef, and the surf was heavy. The tidal pool in which the Hunter had first encountered the boys no longer existed; storms had shifted the sand banks which had outlined it. The boys decided rather quickly that they had had enough. They emerged from the water, bundled their clothes into their shirts, and set off down the beach carrying the garments. Before they had gone far, the Hunter took advantage of Bob’s gazing momentarily out to sea to advise him in strong terms to don, his shoes. The boy allowed his common sense to override minor considerations of vanity, and did so.
The group proceeded for some distance down the beach. After the first few hundred yards, the reef once more sheltered the shore, so the accumulation of flotsam materially decreased; but in spite of this, they had one piece of good fortune—a twelve-foot plank, fourteen inches wide and perfectly sound, had somehow found its way through the barrier and been cast up on the sand. With the damaged boat foremost in their minds, the boys delightedly dragged their treasure above high water mark, and placed a number of pebbles on it in a design signifying “Claimed” to any of the island youths.
Aside from this, the “south shore”—the nearly straight length of beach that extended for some three miles and actually faced approximately southwest—yielded little of interest or value to any of the five youthful beachcombers; and Bob returned to his home somewhat late for supper. The plank had been borne, by the boys united efforts, to the mouth of the creek where the boat was kept; so the only souvenir of the afternoon’s activities Bob brought home with him was the beginning glow of a very complete sunburn. Even the Hunter had failed to appreciate the danger or detect the symptoms early enough to get the boy back into his clothes in time.
The alien, unlike his host, was able to see one good point in connection with the mishap; it might cure the boy of the unfortunate tendency he had been developing, of leaving the care of his body to the Hunter. The latter said nothing of the sort, of course—it might have been taken amiss, as Bob lay awake that night trying to keep as much of himself as possible out of contact with the sheets. He had not been so careless for years, and was inclined to blame it on his coming home at such an odd time. The Hunter did not dispute the matter. He could not have eliminated the pain without the risk of permanent damage to Bob’s sensory nerves, and probably would not have done so anyway.
The next morning several square feet of bright red skin, inclosing an exceedingly disgruntled youth, descended to breakfast in the Kinnaird house; and though the suggestion that Bob should see the doctor was at first met with indignation, the parents found that not too much time was required to crown their efforts at persuasion with success. This pleased them greatly; the doctor had already been informed of the school report, and would be able to deal with that matter less obviously than if the boy had simply gone to see him for a “check-up.” Mr. and Mrs. Kinnaird did not realize that Bob had reasons of his own for wanting to visit the doctor.
In spite of his discomfort, he had spent part of the night considering the Hunter’s problem; and it had occurred to him that he would be much better off knowing more than he did about viruses in general. The Hunter had said his own body cells were of viruslike nature, and it seemed obvious that clues to the whereabouts of the fugitive could be obtained, or even recognized, only by an understanding of the known characteristics of the creature.
There was, to the best of Bob’s knowledge, only one place on the island likely to contain the information he sought; and that was the doctor’s medical library. In consequence, the boy did not have to be persuaded very hard to pay a visit to the doctor.
Dr. Seever knew Bob well, as he had known every other person born on the island from their first squalls. He had read the school doctor’s report, and his opinion of its accuracy chimed very closely with Mr. Kinnaird’s. However, investigation would do no
harm; so he was willing enough to see the youth. He expressed sympathy with the sunburn where Bob had expected the ridicule he deserved, and the conversation from that point flowed smoothly as if rehearsed. Each had something he wanted said, for purposes of his own; and within a very few minutes a number of the doctor’s medical books were open on the desk while the two human beings and their invisible companion looked through them in search of answers to the boy’s questions—the doctor knew many of them, of course, but no one on earth could have supplied the answers to all. At the same time, the doctor was drawing conclusions of his own from the intense scientific interest suddenly displayed by a person he had always considered, if anything, less than ordinarily bookish in tastes. Actually, the doctor was more satisfied with the results of the interview and examination than was Bob.
The former had become reasonably certain that the boy’s apparent change in personality had been a momentary phase, caused probably by the abrupt rousing of his interest in a group of subjects to which he had been an almost total stranger—he was far from being the first adolescent whose mind had spent a few weeks from time to time prowling through some new field of interest. Bob, on his part, had learned a good deal about viruses—as understood by human medical science—they were, he gathered, the smallest bits of living matter known. They were not, in fact, always living; apparently they had been actually crystallized, left in that state for long periods, and resumed their activities of feeding and reproduction when once again dissolved. They were supposed to consist of single protein molecules of enormous weight, though Bob lacked the knowledge of basic chemistry necessary to appreciate the figure to the full. If such a molecule could live, as a single-celled animal can live, there seemed no valid reason why a whole order of metazoan life could not develop with the virus molecule instead of the cell as its basic unit. Bob did not have all these terms at his command, but he could picture the situation clearly enough to see this possibility. He also saw that, the size of the virus being what it was compared to most life cells, a creature could be as complicated in cellular structure as a human being without being much more than microscopic in size. Nothing that he found in the doctor’s books led him to doubt the Hunter’s being exactly what he had claimed to be.
As far as the detection of viruses went, the books had not been so helpful. Usually a disease of unknown origin was “ascribed” to a virus; in only a few cases had the actual agent been isolated. There might be—probably were—uncountable hordes of the quasi-living things inhabiting the bodies of everything that grew or moved, without giving sign or token of their presence. Only a few of the thousands of species of bacteria produce disease; why should all the viruses?
The few actually identified had been isolated chemically and this seemed to offer no help whatever in the Hunter’s problem. It did not seem likely that blood or tissue samples could be obtained from a suspected human being, that the alien would permit any portion of himself to be included in such a sample, or that the tissue of the Hunter’s race could be distinguished from any other virus by the rather crude centrifugal methods described in the doctor’s books.
There are other means of identifying the species from which a tissue sample has been taken; however, the doctor had made some reference to serum tests. Bob had not dared to ask for much detail, fearing that the motive of his curiosity might be questioned; but from the little that had been said, the serum method might overcome the last of the three objections to the chemical test.
Then ‘there was analysis of wastes—but even Bob’s untrained mind could envision the rigid feeding control such a process would entail. He knew little or nothing about basal metabolism; if he had thought of it, he would probably have realized that the absence of control values would have nullified its usefulness in the present case.
And every one of these more than doubtful methods had one glaring fault; not one gave a clue that suggested where to start looking. They would have had to be applied to a whole population, and rack his brains as he might, Bob could think of no test whatever to which this sad fact did not apply.
Some viruses, of course, can be detected by the diseases they produce; but this very definitely did not apply to the Hunter’s species. On the contrary; and you can’t arrest a man on suspicion because he isn’t sick. Any suspiciously sudden case of recovery from chronic illnesses would have to be investigated, of course; but that would not account for a very large fraction of any population—except perhaps a leper colony.
Selective poisons? At this point Bob put a question to the Hunter. They had left the doctor’s home, and were rolling leisurely along the road toward the Kinnaird house.
“Hunter, a lot of human beings drink alcohol; and I remember when the nurse put some on that cut on my arm, it bothered you a good deal. Would that help us find your fugitive?”
“Alcohol in the concentration that touched me on that occasion would certainly ‘force our friend to leave his host’,” the answer came slowly. “However, anything like that concentration would destroy your tissues just as effectively. I have gathered from reading that some of your people can live with rather startling amounts of that chemical in their blood streams; and I would be willing to assume that our quarry is not in the body of anyone who drinks it heavily and habitually. I would have to make tests, however, to be sure whether a single binge would be harder on the host or the symbiote.” The Hunter did not always recognize slang when he saw it.
“If you are a virus yourself, would there be any virus diseases that would affect your kind but not a human host?”
“Very possibly. On my home world we have learned to overcome all the ordinary types; but the virus molecule is very susceptible to influences producing mutation, and we frequently encounter types which cause us trouble. I have had no, trouble with any of the numerous varieties that were in your body, but it would be foolish to ignore the possibility. If I encounter one, and can adapt myself to it before it kills me or forces me to withdraw from you, and if it is harmless to your tissues, such an organism could be useful to us. That leaves quite a bit in the lap of chance, however. I take it you have been endeavoring to solve by yourself the problem of locating my quarry?”
Bob admitted that this was the case.
“You are doing well, considering that the field is so new to you. I don’t mind admitting that the rather unorthodox setting of this problem is bothering me somewhat, though I shall probably be able to adapt some standard procedures to it eventually. Any thoughts you may have will be welcome, however.”
Bob’s self-confidence was considerably elevated by this conversation, though his trust in the Hunter’s weird abilities was somewhat shaken by the discovery that some diseases might be too much for his protector. He had, as the Hunter feared, developed a subconscious tendency to look on the alien as practically a guarantee of invulnerability.
The Hunter’s method of conversation had speeded up somewhat with practice, but even so this brief dialogue had lasted all the way home from the doctor’s. Bob ran the bicycle under the porch and went indoors. The jeep had been standing outside, so he was not surprised to find his father there, though it was an unusual time for him to be at home. Bob found both his parents in the living room, reported as accurately as he could what the doctor had said, and then asked what had brought Mr. Kinnaird home so early in the day.
“I came home to get some food,” was the answer. “Your friends probably told you that there was a new tank going up on Round Hill. They want to start pouring the south wall tomorrow, and the retainers have to be finished and checked. We’ll certainly be all day, and probably most of the night, on it.”
“May I go along?” asked Bob. “I may be some help, and it’s too late to go to school today—it’s Friday anyway. Is this tank any different from the one they set up last year?”
“No important difference. You might as well come along: If you aren’t able to avoid dropping planks on your toes and falling off retaining walls, it’s time I found it out. Your mother wil
l double the lunch order, I expect.”
“As a special favor,” Mrs. Kinnaird laughed, and vanished into the kitchen. She was in unusually good spirits; the doctor had already telephoned to the effect that the only thing probably wrong with her son was a sunburn. She reappeared quickly with cold meat and milk, and returned to the kitchen to make sandwiches.
In the living room, Bob and his father were in deep conversation. Once again the boy had forgotten his mission, and was asking about the new culture tank—he had been away at school when the one to which he had referred in his question had been installed. The Hunter paid little attention; he already had a pretty clear notion of the working and construction of the tanks, and in any case would shortly be able to see for himself. He was considering more deeply the suggestions made by Bob a few minutes ago, and wondering whether anything could be made of them. That alcohol idea, now—. Of course, the only really trustworthy selective drugs were serums, and they could hardly be obtained; and allergens were too unpredictable, though the Hunter could probably isolate some of those himself.