by Hal Clement
"O.K., Mother, I'll try to hit a happy medium."
He went back up to his room after breakfast and donned an old long-sleeved khaki shirt of his father's instead of the T-shirt he had originally worn, came back and helped his mother with the dishes-his father had already driven off-spent a while fighting the ropy jungle growth which persistently threatened to overwhelm the house, and finally put away clippers and hormone spray and vanished into the tangle south of the dwelling.
His course carried him gradually farther from the road and distinctly uphill. He traveled as though with a definite purpose in mind, and the Hunter forbore to question him-the background of jungle was not very suitable for his method of communication anyway. Shortly after leaving the house they crossed a brook, which the detective correctly judged to be the same watercourse that was bridged by the road a little lower down. A fallen tree, whose upper surface bore signs of frequent use, crossed it here.
Mrs. Kinnaird had not exaggerated the nature of the jungle. Few of the trees were extremely tall, but the ground between them was literally choked with smaller growths, many of them, as she had said, viciously thorned. Bob threaded his way around these with a speed and skill that suggested long experience. A botanist might have been puzzled by many of the plants; the island bore a botanical and bacteriological laboratory in which work was constantly in progress to improve the oil-making bacteria and to breed better plants to feed the tanks. Since what was desired was very rapid growth with a minimum of demand on the mineral content of the soil, the test plants occasionally got out of hand.
The place Bob intended to go was barely eight hundred yards from the house, but the journey took more than half an hour. Eventually they reached the edge of the jungle and the top of the hill, and found themselves looking down toward the settled portion of the island. Where the jungle had been stopped by hormone sprays to make room for the gardens was a tree, taller than any they had seen in the jungle itself, though not so high as the coconut palms near the shore. Its lower branches were gone, but the trunk was ringed with creepers that made a very satisfactory ladder, and Bob went up without difficulty.
In the upper branches was a rough platform that indicated to the Hunter that the boys had used the place before; and from here, well above the general level of the jungle, practically the entire island was visible. Bob let his eye rove slowly around the full circle, to give the Hunter every chance to fill in details that had been lacking on the map.
As the Hunter had thought from his glimpse up the road the day before, there were some tanks on shore on the northeast end of the island as well. These, Bob said when questioned, housed bacteria which worked so much better at high temperature that it was worth while to have them up in the sunlight and accept the fact that their activity would stop at night.
"There seem to be more of them than there used to be," he added. "But, then, they're always doing work of one kind or another. It's hard to be sure-most of them are on the far slope of the northeast hill, which is about the only part of the place we cant see very well from here."
"Except objects in and near the edge of this jungle," remarked the Hunter.
"Of course. Well, we couldn't expect to find our friend from a distance, anyway; I came up here to give you a better idea of the layout. Well have to do a good deal of our searching in the next three days; I certainly can't put off school longer than Monday." He nodded at the long building down the hill. "We could go looking over the reef now if the boat were in shape."
"Are there no other boats on the island?"
"Sure. I suppose we could borrow one, though it's not too smart to poke around the reef alone. If anything happens to the boat, or a person bashes himself falling on the coral, it's apt to be too bad. We usually go in boatloads."
"We might at least look over some of the safer portions, if you can get a boat. If not, can any parts near your beach be reached on foot?"
"No, though it wouldn't take much of a swim to get to the nearest part. I'm not going to swim today, though, unless you can do a good deal more about sunburn than you have done."
He paused a moment, and went on, "How about the other fellows? Did you see anything about them yesterday that might make it worth while to try firsthand testing?"
"No. What would you expect me to see?"
Bob had no answer to that, and after a moment's thought slowly descended the tree. He hesitated for a moment more at the bottom, as though undecided between two courses of action, then he headed downhill, threading his way between garden patches and slanting gradually toward the road. He explained his hesitancy with: "Guess it isn't worth the trouble to get the bike."
They reached the road about two hundred yards east of the school and kept going in that direction, Bob glancing at the houses they passed as though estimating his chances of borrowing such a thing as a boat from the occupants. Presently he reached the road which led down to the dock, with the Teroa house at the corner, and Bob quickened his steps.
He walked around to the shoreward side of the dwelling, rather expecting to find Charles working in the garden, but the only people there were the two girls of the Teroa family, who said that their brother was inside. As Bob turned toward the house the door was flung open and Charles burst out.
"Bob! You doubting Thomas! I've got it!" Bob looked slightly bewildered and glanced around at the girls, both of whom were grinning widely.
"Got what?"
"The job, fathead! What were we talking about yesterday? A radiogram came this morning. I didn't even know there was an application in it-I thought I'd have to try all over."
"I knew." Bob grinned. "Your father told me."
"And you didn't tell me?" Teroa reached out for him and Bob moved back hastily.
"He said not to-you weren't supposed to know. Anyway isn't this better than sweating it out?"
Teroa relaxed, laughing. "I suppose so. Anyway, that red-headed friend of yours will be mad-it's what he gets for backing out!"
"Redhead? Ken? What has he to do with it? I thought it was Norman went with you."
"It was, but it was Rice's idea, and he was supposed to come along. He got cold feet or something and never showed up. Can I razz him now!" He turned suddenly serious. "Don't you tell him about this job. I want to!" He started to walk toward the dock, then turned back. "I'm going out to Four to collect something Ray borrowed a while back. Want to come along?"
Bob looked at the sky, but the Hunter expressed no opinion, and he had to make up his own mind. "I don't think so," he said. "The barge is a little ripe for my taste." He watched as the brown-skinned eighteen-year-old disappeared among the storage sheds, then turned slowly back up the road.
"That was our only real chance for a boat," he said to the Hunter. "We'll have to wait until the fellows get out of school. As a group, we stand a better chance of borrowing one-or maybe it won't take long to fix our own. I didn't have time to look at it very closely when we took the plank down yesterday."
"Was that boy going to use his own boat?"
"Yes. You heard him say he was going out to Four- that's Tank Four-to get something. The person he mentioned works on the barge they use for carrying the tank wastes. Charlie wants to collect from him before he leaves the island."
The Hunter was instantly alert. "Leaves the island? You mean the bargeman?"
"No-Charlie. Didn't you hear what he was saying?"
"I heard him talk about a job, but that was all. Is it taking him away?"
"Of course! Charlie's the son of the mate of that ship-the one who stowed away, hoping to get a job on her! Don't you remember-his father told us the first night, on the ship!"
"I remember your talking to an officer on the tanker," the Hunter replied, "but I did not and do not know what you said. You were not talking English." Bob stopped short and whistled.
"I forgot all about that!" He paused a moment to marshal his thoughts, and told the story as briefly and clearly as he could. The Hunter thought for a time after he had finishe
d.
"Then this Charles Teroa has left the island once since my arrival and is shortly to leave it again. Your friend Norman Hay has also left once. For Heaven's sake, if there are any others you've heard about, tell me!"
"There aren't, unless you want to count Charlie's father, and I don't suppose he's been ashore here much. What does it matter about the other trip? They never got ashore, you know, and I'm sure they didn't sleep in port, so if our friend was with them he couldn't have left except at sea."
"You may be right, but that will no longer be true for this one you just saw. He must be examined before he leaves! Start thinking, please."
For the first time that day Bob completely forgot his sunburn as he walked back up the road.
Chapter X. MEDICAL REPORT
BOB MANAGED to hide his concern at lunch; his mother had thought of something during the morning to take his mind off the new problem. She had been wondering how to persuade her son to have a checkup by the island doctor, and had realized just after he disappeared what a splendid excuse the sunburn provided. She had no opportunity to discuss it with her husband, since Bob had arrived home first, but he would probably have agreed with her anyway. She brought up the subject as they finished the meal.
She did not really expect to win without argument; she knew Bob was ashamed of having acquired the sunburn and did not want more people than were strictly necessary to know about it. She was therefore somewhat astonished when her son agreed without a murmur to the suggestion that he drop into the doctor's office that afternoon, though she had the control and presence of mind not to show it.
The fact of the matter was that Bob had been thinking about the Hunter's failure to answer certain of his questions, particularly those which dealt with the details of how he was to recognize his quarry and still more, what he was to do after the creature was found. If the Hunter knew, well and good; but the suspicion that his invisible guest did not know was growing. It followed that Bob must get some ideas of his own; and for such ideas to be any use, he must learn more about the Hunter's species. The alien had said he resembled a virus. Very well. Bob would find out about viruses, and the logical place to do that was in a doctor's office. He had known it would be somewhat out of character for him to make the suggestion himself, but it did not occur to him to wonder that his mother should have done so; he simply accepted it as a piece of luck.
Dr. Seever knew Bob very wellas he knew every other person born on the island. He had read the communication from the school doctor, and agreed with Mr. Kinnaird's opinion of it; but he was glad of the chance to see the boy himself. Even he, however, was a little startled when he saw the color of Bob's skin.
"Good heavens! You really celebrated getting back here, didn't you?"
"Don't rub it in, Doc. I really know better."
"I should think so. Well, well tan your hide for you- not the way it ought to be done, but you'll be more comfortable." The doctor set briskly to work, talking steadily the while. "You certainly aren't the fellow you used to be. I can remember when you were one of the most thoughtful and careful people here. Have you been sick lately at that school of yours?" Bob had not expected the question so soon or in just this form, but he had made plans for putting it to his own use when it came,
"Certainly not. You can look me over all day and won't find any germs at work."
Dr. Seever looked over his glasses at the boy. "That's certainly possible, I know, but is hardly assurance that nothing is wrong. It was not germs that caused that sunburn, you know."
"Well, I sprained an ankle and had a cut or two, but they don't count. You were talking about sickness, and you could find out about that with your microscope, couldn't you?"
The doctor smiled, conceiving that he knew what the boy was driving at "It's nice to find someone with such touching faith in medical science," he said, "but I'm afraid I couldn't. Just a minute and I'll show you why." He finished applying the sunburn material, put the container away, and brought an excellent microscope out of its cabinet Some searching among rather dusty slide files found what he wanted, and he began slipping the bits of glass onto the stage one after another as he talked.
"This one we can see, and recognize, easily. It's protozoan-an amoeba, of the type that causes a disease called dysentery. It's big, as disease-causing organisms run."
"I've seen them in bio class at school," Bob admitted, "but I didn't know they caused disease."
"Most of them don't. Now this"-the doctor slipped another slide under the objective-"is a good deal smaller. The other wasn't really a germ at all. This causes typhoid fever when it gets a chance, though we haven't had a case in a long time. The next is smaller still and is the cause of cholera."
"It looks like a sausage with the string still on one end," Bob remarked as he raised his head from the instrument.
"You can see it better with the high-powered objective in place," Dr. Seever remarked, turning the turret at the lower end of the instrument and sinking back into his chair while Bob looked once more.
"That's about as far as this gadget can go. There are many smaller bacteria-some of them harmless, some not. There is a class of things called Rickettsia which are smaller still and may not be bacteria at all, and there are viruses."
Bob turned from the microscope and attempted the difficult feat of looking interested without showing that the conversation had finally reached the point he wished.
"Then you can't show me a virus?" he asked, knowing the answer perfectly well.
"That's what I'm getting at A few of them have been photographed with the aid of the electron microscope- they seem to look a little like that cholera bug I showed you-but that's all. As a matter of fact, the word 'virus' was simply a confession of ignorance for a long time; doctors were blaming diseases which seemed to be life-caused for one reason of another, but for which they could find no causative organism such as I've shown you, on what they called 'filterable viruses'-so named because no matter how fine a filter you squeezed the juice from a diseased creature through, the cause seemed to go through with it They even found ways to separate the virus stuff chemically and crystallize it; it would still cause the same disease when the crystals were dissolved in water again. They devised a lot of very pretty experiments to guess at the sizes of the things, and their shapes, and other such matters long before they saw *em. Some scientists thought -and still think-they are single molecules; big ones, of course-even bigger than the albumin ones-that's the white of egg, you know. I have read several darn good books on the subject; you might like to do the same."
"I would," replied Bob, still trying not to seem too eager. "Do you have any of them here?" The doctor got out of his chair and rummaged through another cabinet, eventually emerging with a thick volume, through which he leafed rapidly.
"There's a good deal here but I'm afraid it's a bit technical. You may take it if you want, of course. I had another that was much better in every way from your standpoint, but I guess I've already let it out"
"Who has it?"
One of your friends, as I recall-young Norman Hay. He's been getting interested in biology lately. Maybe you heard about his trying to get to the museum on Tahiti. I don't know whether he's after my job or Ranee's over at the lab. He's had the book quite a while-several months, I think; if you can get it from him, take it"
"Thanks; I will." Bob meant the statement earnestly. "You couldn't tell me offhand more about the chemical separation you mentioned, could you? It sounds funny, identifying a living creature by chemistry."
"As I said, there's some doubt as to whether we should call the viruses living creatures. However, there's nothing unusual about the tests you mention. Haven't you ever heard of serums?"
"Yes, but I thought they were stuff that you used to make a person immune to some disease."
"That is frequently the case. However, a better way of looking at them is more or less as chemical fingerprints. The tissues of one type of creature try to fight off serums made from the
tissues of another. You can get an animal used to human serum, for example, and then tell from the reaction between the serum of that animal and some unknown substance whether the substance contained human tissues or not. The details vary, of course, but that's one way of telling whether a bloodstain or other organic trace came from a man or some other animal."
"I see-I guess." Bob's eyes were narrowed in thought "Does this book have anything about that?"
"No. I can give you something on it, but I warn you it's a little beyond high-school chemistry. Whose job are you after?"
"What? Oh, I see. Not yours, anyway. There was a problem I ran across, and I'd like to solve it myself if I can. If I can't, I'll be back for more help, I expect. Thanks, Doc."
Seever nodded and turned back to his desk as Bob went out; and for several minutes the doctor meditated.
The boy was certainly more serious than he had been. It would be nice to know just what his problem was. Very possibly-even probably-it accounted for the personality change that had worried the school authorities. That, at least, would be a comforting report to give the boy's father; and that, later in the afternoon, was just what the doctor did.
"I don't think you need worry at all, Art, if you were. The kid's gotten himself interested to the hilt in something that appears to have a scientific flavor-young Hay did the same a few months ago-and will simply soak it into his system. You probably acted the same, the last time you learned something big. He's presumably going to change the world, and you'll hear about it in due time."
Bob had no intention of changing the world to any great extent, not even the human portion of it. However, some problems which had arisen in the course of the afternoon's talk might make changes to individuals necessary, and once out of the doctor's office he wasted no time in putting them up to the Hunter.
