They made their way up to the construction site, amusing each other the while with speculation on the troubles the others would be having getting the swamped boat through the breakers at the beach, and began prowling for materials. These proved fairly plentiful, and well before suppertime they had placed the articles of their choice in a number of inconspicuous places, to insure their remaining unused until after school the next day. They were honest youngsters, in their way.
Two things happened to prevent Bob's getting back to the site immediately after school. One of them occurred Monday morning, when his father saw him limping as he descended to breakfast, and demanded the cause. Bob repeated the story he had given Hay; but the next demand was a little awkward.
"Let's see it." Bob, thinking fast, pulled his trouser leg halfway to the knee, exposing the entry wound. This, of course, did not look nearly so bad as it should have, since the Hunter had held the torn skin in place all night and was still on duty. To the boy's vast relief Mr. Kinnaird did not ask about the depth of the injury, taking for granted that nothing so obviously free from blood clots and infection could have been very deep. The relief was short-lived, however. The man turned away, saying, "All right. If you're still limping the next tune I see you, you'd better be able to tell me you've seen Doc Seever." The Hunter's respect for Mr. Kinnaird was increasing daily.
Bob set out for school with that problem on his mind -nothing was more certain than the fact that his torn calf muscle would keep him limping for days to come, Hunter or no Hunter; and his father would certainly be at the construction site that afternoon. At the end of school another cause for delay materialized: the teacher who handled the older pupils requested that he remain for a time, so that his proper position in the group might be discovered. Bob requested a moment's excuse, hastily explained to the others, and saw them started for the new tank; then he returned to the schoolroom for the inquisition. It took some time. As frequently happens when a pupil changes from one school to another, the difference in programs had put him a year or so ahead in some subjects and as far behind in others. By the time a mutually satisfactory program had been worked out, Bob was pretty sure his friends would have obtained what they needed and taken it to the creek.
Even so, there remained the problem of the limp and his father's ultimatum. He had been trying all day to walk as though nothing were the matter, and had succeeded only in attracting more attention. He stood at the doorway of the school for some minutes, pondering this problem, and finally put it up to the Hunter. He was distinctly startled at the alien's answer.
"I suggest that you do exactly what your father said- go to Dr. Seever."
"But how can we get away with that? He's no dumbbell, and you won't make him believe in miracles. He won't be satisfied just to see one of those holes, either-hell check the whole leg. How will I account for the shape it's in without telling about you?"
"I have been thinking about that. Just what, would you say, is wrong with the idea of telling him about me?"
"I don't want to be written off as cracked, that's what I had trouble enough believing in you myself."
"You'll probably never have better evidence for your story than you have right now, if the doctor is as thorough as you say. I will back you up; and / can prove I am here to anyone's satisfaction, if necessary. I know we have been making strenuous efforts all along to keep my presence secret, and the reasons for that are still sound; I don't mean to broadcast the story. I think, however, that a doctor might be a remarkably good associate in our work. He has knowledge neither of us possesses and should be willing to use it-it is certainly no exaggeration to describe our quarry as a dangerous disease."
"And if he turns out to be the host of our quarry?"
"He is certainly one of the least likely candidates on the island. However, if that should be the case- I think I can find out very quickly and certainly. There is certainly a precaution we can take." He outlined this precaution at length to his host, and Bob nodded slowly in understanding.
The doctor's office was not far from the school. It would hardly have been worth using the bicycle had it not been for Bob's injury. There was a slight delay caused by the presence of another patient, then Bob and his invisible guest entered the pleasant room which Dr. Seever had turned into a consulting room and dispensary.
"Back again so soon, Bob?" greeted the doctor. "Is that sunburn still giving trouble?"
"No, sir, I'd forgotten about that."
"Not entirely, I hope." The two grinned in sympathy.
"This is something else. I had a fall in the woods yesterday, and Dad said I'd better either see you or stop limping."
"All right, let's see the damage." Bob seated himself in a chair facing the doctor and rolled up his trouser leg. At first Dr. Seever did not see the exit wound, but after a moment he did. He examined both openings carefully and at considerable length, then he sat back and eyed the boy.
"Let's have the story."
"I was up in the woods, near the head of the first creek. The bank had been undercut farther than I thought, and I broke through, and a sharp-pointed branch underneath went into my leg."
" Through' is the word you want. Go on."
"There's not much else. It hasn't bothered me too much, so I didn't come to you until Dad made me."
"I see." The doctor was silent for another minute or two. Then, "Did something like this happen at school back in the States?"
"We-e-11-" It never occurred to Bob to pretend not to know what the doctor meant "There was this." He extended the arm that had been cut the night the Hunter had made his first attempt at communication. The doctor silently examined the thin, barely visible scar.
"How long ago?"
"Three weeks about." Another period of silence, while Bob wondered what was going on in the other's mind. The Hunter thought he knew.
"You've discovered, then, that there's something unusual about you-something you couldn't understand; something that made injuries which should need stitches behave like scratches and punctures that should put you flat on your back 'not bother you much'; and you've been worried about it? Was that what got into you at school?"
"Not exactly, sir. You're almost right, but-I know what causes it." With the Rubicon crossed, Bob went ahead quickly and clearly with his story, and the doctor listened in rapt silence. At the end he had some questions.
"You have not seen this-Hunter yourself?"
"No. He won't show himself to me. Says it might disturb my emotions."
"I think I can see his point. Do you mind being blindfolded for a little while?" Bob made no objection, and the doctor found a bandage and tied it over his eyes. Then: "Please put your hand-either one-on the table here, palm up; let it relax. Now-Hunter, you understand what I want!"
The Hunter understood clearly enough and acted accordingly. Bob could see nothing, of course, but after a moment he felt a faint weight in the palm of the extended hand. His fingers started to close on it instinctively, and the doctor's hand promptly descended to pin them in place. "Hold on a moment, Bob." For a short time the weight could be detected, then the boy began to doubt whether or not it was actually there-it was rather like a pencil stowed behind the ear, which can be felt after it is gone. When the blindfold was removed, nothing was visible, but the doctor's face was even more sober than before.
"All right, Bob," he said. "Part of your story appears to be true anyway. Now, can you enlarge on this mission of your friend?"
"First, there is something I have to say," replied Bob. "This is really his speech, and I'll try to give it in his own words, as near as I can remember.