About a third of the metal surface was exposed, and about as much more was so thinly covered with marine growth that its underlying shape was still plain. From the rest, the limy branches grew in random contortions which even the alien found decorative; the branches were covered with the ribbed cups that had once contained living polyps. On the bare metal were patterns of fine scratches which were perfectly legible to the Hunter, though only their essential regularity was apparent to the human beings. .

The mere fact that the manufacturer's name, serial number, and various sets of mounting and servicing instructions were present was not the peculiarity which had caught the Hunter's attention the day before. Far more surprising to him was the uniformity with which each of these areas of engraving was ex- posed to view. There were no partly hidden words or phrases or numbers. Each symbol or group of symbols was completely free of coral and other growth, as was the metal for several millimeters around it. The coral did not seem to have been broken away, but it might possibly have been dissolved.

After waiting for some minutes for his host to notice this, the Hunter posed several leading questions. These also failed to bring Bob's attention to the strange regularity, and the alien finally gave, up and pointed it out. Then, of course, it was perfectly clear to the man, and he couldn't understand why he had failed to notice it before.

"Well, you see it now," said his symbiont. "Now let's find out if it was that way when Miss Teroa found it, or if it has become that way since." He left Bob with the problem of executing this simple request.

Logically, the man started with the most general questions possible. "Mae, are you sure nothing has changed about this thing since you found it?"

"Not perfectly sure, but it definitely hasn't changed very much.

Certainly no branches are broken. I admit I don't remember either the exact branch pattern or the arrangement of the patches of bare metal well enough to draw a picture, but if either of these has changed, I don't think it can be very much, either."

"The metal looks the same?"

"As far as I can remember. I'm afraid metal is just metal to me, unless it has a real color like copper or gold."

Bob saw no choice other than to get specific. "I was wondering about the scratches on the metal. They seem to be only on the bare parts-they never run out of sight under the coral. Of course there may be some scratches entirely under it, but it looks sort of as though someone had been making marks on the steel or whatever it is after the coral had grown."

"I see what you mean." Maeta nodded thoughtfully. "I don't remember really noticing the scratches before; maybe someone has been at it. I doubt it, though. The case it's been on is pretty high for young children to reach, and I don't think an adult would spoil it that way." Maeta, like Jenny, had not taken the college option, and for a brief moment Bob was startled by her naivety. He made no comment, however, even to the Hunter.

They moved around the table, examining the object from all sides. If any bit of the engraving was hidden at all, it was completely hidden, as Bob had said. This, the Hunter felt sure, could not possibly be a matter of chance; and from the near despair of that morning, when Bob had awakened with the joint pains, the Hunter suddenly felt happier than he had in two Earth years. Perhaps that was why he made a mistake.

"Bob," he said. There can't be any doubt. It can't be an accident. Those areas were uncovered carefully, using acid, to let someone read the engraving, and only my own people could either have expected to find anything to read or have counted on understanding it after it was uncovered!"

It was a forgivable mistake-not the logic, which was perfectly sound, but the failure to see the results of the remark. After all, Bob had seemed to be taking the situation very calmly- unbelievably calmly. If the young man's physical condition had been normal, the Hunter might have been able to spot the emotional tension of his host; but since the alien himself was handling, more or less directly, most of the hormone systems which emotion tends to affect, he had failed to do so. Bob's reaction took both of them by surprise. "Then they are here!" he exclaimed happily-aloud. Jenny understood, naturally. Maeta, just as naturally, didn't, and was understandably surprised.

"Who is here?" she asked. "You mean you recognize the sort of ship this came from? That doesn't prove anything-I found this years ago, remember."

Bob covered fairly well, but not perfectly. "That's true," he admitted. "I wasn't thinking for the moment. Can you remember just when that was? You told us pretty well where."

The young woman was silent for some time, the rest watching with varying degrees of patience.

"Let's see," she said slowly at last. "The library was finished early in '51-I remember because I started to work here after school, as soon as it opened, and my first working day was my sixteenth birthday. I'd had this thing quite a while then. A year? No, longer. I never went out in the Haerehaere very often-the first time I was only twelve, and that was the year you came home so early and stayed so long, and when Charlie got his first ship job."

Bob nodded encouragingly, but managed to keep quiet this time. The year he had "stayed so long" was the one in which the Hunter's first problem had been solved. Maeta went on.

"It must have been some time in March, either '48 or '49-oh, I remember. I'd been taking care of your sister a lot, and she was walking then, so it must have been March of '49, a little over five years ago."

"Good. Beautiful. Thanks a lot."

"So they, whoever they are, may have been here then, but they don't have to be here now," finished Maeta.

But Bob and the Hunter were sure they knew better.

7. Joke

"Bob, have you time to give us some help?"

The Hunter and his host were both startled. They were still standing around, the table which bore the generator case, but there had been several minutes of silence. Everyone had been pursuing his or her own line of thought, some of which had led pretty far from Ell. Maeta's question had not been an interruption, however, since neither Bob nor the Hunter had found a really promising line of thought to follow.

"I guess so," Bob answered. "What is it?"

"Those books you brought back have been brought to the library, and we have to catalog and shelve them. Can you help with the sorting? I'll recognize subjects all right; but we like to have some estimate of scope and difficulty. You've read them-I suppose."

"For the most part," Bob grinned. "All right, I might as well.

Jenny, you want to stay and help?"

"No, thanks, I'm not at home in college books, and might feel lost-at least, I wouldn't be much help. I'll go ask Mr. Tavake that question we didn't get around to yesterday."

"All right, good idea." Bob read nothing between the lines of her refusal to stay. "Will you be home afterward? I think it's time we talked things over with your father. The next part of the job won't be easy even if Tavake comes through."

Jenny hesitated a moment; the Hunter a.s.sumed, she had made other plans and was weighing their importance. Bob gave no thought to the pause.

"All right," she finally said. "I'll see you-when? A couple of hours, Mae?"

"The whole job will take days, but that much will get us started," the older girl replied. "If this other thing you're talking about is important, my job can wait-or I can do it all myself, though probably not as accurately."

"We're hung up for the moment on our thing, anyway," Bob a.s.sured her. Even the Hunter knew that both Bob and Maeta were merely being polite. He was much less sure about Jenny.

Unavoidably, Bob stayed and the redhead departed.

Maeta led the way downstairs. The book crates had been placed beside a large table in a bas.e.m.e.nt room. While it was not regularly used by the library patrons, the walls were lined with partly filled bookshelves. The table was loaded with pots of adhesive, scissors, tape, and similar library equipment, and one corner of the room was occupied by a large, very comfortable- looking armchair with a small table beside it. Maeta looked at these and smiled.

"This was set up as a study for Mr. Thorvaldsen when the library was built, but he fell asleep in the chair so often that he decided to use his old place in the laboratory building. We've taken it over for book processing. How many do you think you have here?"

"Don't remember exactly. They're not all course texts. I was told I could buy other stuff which was recommended to us as reference material; that's why I can't say I've read every last page of it. I guess the easiest thing is to get it all out on the table and start sorting by subject, unless librarians have some more; ingenious way of doing it." Maeta glanced at him, but had nothing to say to his closing remark, and they started as he had suggested. The girl worked quickly and efficiently, and made good use of Bob's knowledge.

She said nothing about the remarks Bob and Jenny had made while they were upstairs, but the Hunter felt sure she was thinking about them. The young woman was obviously far too intelligent not to be curious. The alien was thinking about her more and more as the morning wore on, not only about her evident brains but also about her competence-remarked upon the night before-on and in the water. She could be useful, if Bob's prejudices could be submitted to another blow.

But Bob was getting harder to persuade with each new recruit.

It might be necessary to manage Bob for his own good. Jenny would be willing to do that, in principle; but of course there was some difficulty in speaking to Jenny. The Hunter thought deeply, and did not regard the library session as time wasted.

For most of the two hours, Maeta said nothing not directly connected with the job, but just before the session ended she changed the subject briefly.

"Bob, did you say anything to Jenny which could make her think you were laughing at her, or looking down at her, because she hadn't been to college?"

"Not that I can remember. I certainly didn't mean to." Bob's surprise was quite genuine. "What makes you ask?"

"I know she's sensitive about not getting accepted by any college and something she said when she was leaving a while ago made me wonder whether you'd twisted the knife."

"Well, I never thought about it. I didn't even know she'd applied for a college. Why should staying here bother her? Lot's of people don't go-you didn't, and you're older than she is, and it doesn't seem to bother you. Shorty didn't, and it certainly doesn't bother him!"

"Shorty? Oh, the Malmstrom boy." That was an interesting way to put it, since Malmstrom was three years or so older than Maeta.

"I don't know much about him. I never applied to a college, and didn't have to face a rejection. I'm perfectly happy here. I like to learn things, and in this library I'd be lifetimes just catching up with what's available. There's just nothing else I want which might take me away from Ell. But Jenny isn't that way, and please be careful what you say to her."

"All right Thanks for telling me."

Bob took Maeta's admonition at face value, but the Hunter felt there must be something behind it. He tried to puzzle out the possibilities as they went upstairs. Perhaps Maeta felt genuinely protective about Jenny; the redhead was younger, though only by a year or so. She might, on the other hand, be more concerned with Bob and his tendency to be just a little too pleased with his brand new degree, a tendency of which the Hunter was quite aware. He could see no reason why Maeta should be particularly interested in Bob-or rather, while he could see one, he considered it unlikely on such short acquaintance. He had heard it said that females had a general tendency to try to remold any available males, but since the speakers had always been males, he had placed little weight in the claim. He considered it biologically unlikely that there would be major psychological differences between the two human s.e.xes, other than superimposed cultural ones.

He would probably have dismissed the question as both unimportant and insoluble anyway, even if his attention had not been sharply distracted.

Bob had used his bicycle for the mile-and-a-half trip from his house. Maeta had accompanied them to the library door, though she was planning to go back to do more work on the books, and Bob was looking back to utter conventional farewells as he swung aboard his machine. A second later he was sprawled on the concrete.

The Hunter had the damage categorized at once; his host had severe sc.r.a.pes on the left knee, shoulder, and elbow. He was not quite so quick at deciding how much repair and protection to supply. Had Bob been alone, he would not have lost a drop of blood; but Maeta and the other witnesses who had immediately collected might not be able to believe that anyone could suffer such a fall with no damage. Perhaps the Hunter should allow him to bleed a little-not enough to cause real damage, of course-for the sake of appearances.

On the other hand, the concept of "luck" was widely accepted among human beings, he reflected, and he had noticed that many of the species could dismiss the most incredible events from their minds simply by using this word. The Hunter decided to take the chance. He followed his natural inclinations, sealed off all blood leaks, and got to work on the microorganisms they had picked up.

His partner, surprised, though he was, had picked himself up before anyone actually reached him. His first reaction was one of extreme embarra.s.sment, not helped by the words of one of the juvenile witnesses.

"You'd think anyone would look where be was going on a bike, even with a girl around, wouldn't you?"

"I was just-" Bob stopped talking at once, realizing there was nothing he could possibly say which would not furnish more ammunition for a ten-year-old.

"What happened, Bob?" Maeta had returned by now. "Are you hurt?"

"Not physically. My ego will take some repair. I don't really know what happened; the bike just went out from under me."

Everyone, including the children who had gathered, cl.u.s.tered more closely to look at the machine was nothing obviously wrong until Bob cautiously mounted it again, and eased it gently forward.

Then it was obvious to all that the handlebars and the front wheel were no longer aligned with the bar straight across, the wheel pointed noticeably to the right. This would ordinarily have made no difference; a cyclist's reflexes operate off in put from the inertial senses and the general visual picture of the terrain. He doesn't keep looking at the front wheel to see where he is going next. In this in stance, however, Bob had not really started to roll when he had put his weight on the left pedal and started to swing his right leg across. He had not noticed the change in the handlebar-wheel relationship before he started to move. Naturally he had started a frantic left turn as he began to fall, but the bicycle was moving far too slowly for this to be effective, and with the wheel near ninety degrees, the entire machine had slid from under him, as he had said.

"A smart person keeps his bike tightened up," remarked the youngster who had spoken before.

"Quite right," Bob agreed, paying no more attention to him. "I'm OK, Mae. See you later." He remounted the machine and started down to the road, not looking back this time.

"Shouldn't you tighten it up?" the Hunter asked, "We have tools, don't we?"

"Sure, in the case," was the reply. "It isn't loose, though."

"But-" The Hunter stopped talking as his mind drew too far ahead of his words.

"Yeah. But. We'll think it over later on." There was no time for more conversation, even if there had been thought to feed it. The journey to the Seevers' was short, and they had already arrived.

Jenny met them at the door. If she had been unhappy about anything when she had left them, there was no sign of it now.

"Come on in," she said cheerfully." Dad's in the office, and we have something to show you." She led the way.

"Seever was sitting at his desk, examining with interest an open box about a foot square and half as deep. It was made of thin wood, with the seams heavily caulked and a gasket on the rim where the lid presumably was sealed. Clearly it was meant to be watertight. It contained a quant.i.ty of obviously electrical equipment-coils, batteries, and vacuum tubes -which told both the newcomers what it must be though the details were far from clear. Bob had of course taken several physics courses on his way to the chemical engineering degree, and the Hunter had paid some attention to both, reading and lectures, but neither had more than the roughest idea how a metal-detector worked.

"That was a quick job!" Bob exclaimed. Seever answered.

"Not exactly. It was made long ago, well before your father asked for it. Tavake's kids have been using it for months. The only reason he didn't hand it over when Arthur asked for it yesterday was that the young ones were out using it. Taro was surprised when Jenny came around today asking for the same thing. He only gave it to her when she explained it was the same project and would get to the same people."

"The word's spreading like a tank leak on the lagoon," growled Bob.

"Oh, no," insisted Jenny. "Mr. Tavake doesn't know what the project is all about. I certainly didn't tell him, and I'm sure your father didn't."

"He certainly knows that something involving several people and his metal-detector is going on. In a place the size of Ell that may not be quite the same as knowing what it is, but it's the same as having every-one know that much-and the ident.i.ties of the people involved. Well, I suppose it can't be helped. But if we have to ask for anything else, let's have just one person do the asking from now on."

"Did you tell Maeta?" asked Jenny.

"No, of course not. But she has to know there's something funny-"

"Well with that slip of yours about 'they must be here', she probably won't ask me what I know, but she'll be asking me whether I know anything. What do I tell her? You were being all pure about lying yesterday, most of the time."

"Tell her the truth, of course," snapped Bob. "That you know, but it isn't your secret." Bob was looking at Jenny as he spoke, and the Hunter regretted not being able to see the doctor's expression.

It would have been nice to be able to guess his reaction to the intimation that his daughter was not always truthful. His voice cut in, but by the time Bob looked toward him he was well on his way with another matter, and the expression was probably irrelevant to the earlier question.

"Please let me know what you do tell her, Daughter. Maeta works here sometimes, remember, and I don't want to make any slips talking to her because of what she has or hasn't been told.

Personally I think she's a very bright young lady who could be a big help to us, but I understand how Bob feels about letting the word spread any farther."

"I knew it," sighed Bob. "Who else, while you're at it?"

"I wasn't making a serious plea about Maeta, Bob, but I did mention Jenny's mother earlier."

"I thought I'd okayed that"

"You weren't really clear, and I didn't want to take a chance until you were."

"Well, tell her. But let's keep it in the families for a while. Of course, if I get so I can't run things, you're the boss and can do what you think best. Now, how does this metal-detector work?"

"You turn it on here. If the earphones whistle, turn the k.n.o.b here until it just stops. Then if it comes close to metal, the whistle starts again. If you don't get a whistle at any k.n.o.b position, put in a new battery. If that doesn't work, take it back to Taro. Nothing to it."

Bob picked up the box. "It's much too light to sink.

How do we ballast it for underwater use?"

Seever pointed to a larger box made of concrete, on the floor beside his desk. What looked like a lid lay next to it. Four eyebolts projected from the sides of the cube, as did an insulated wire; it looked as though the concrete had been poured around these.

Seever's explanation corrected one point; the "lid" was actually the floor of the device. The wooden box was supported well above this, and trapped air would keep any water which leaked in well below the electrical equipment, at least to any reasonable depth, as long as everything was kept upright.

"Taro says it's worked fine for his youngsters," Seever finished.

"He's had no trouble with leaks, and they've found a lot of stuff like dropped tools on the bottom around the dock and the tanks. It sounds off for a pair of pliers at five or six feet when it's really at it's best.

"Now, Bob, tell me if I have everything straight. Jenny says you are now quite sure that the Hunter's people have been on Earth, and on Ell." Bob nodded emphatically.