Needle

If the other were in a human being, that person could leave the island only in some sort of craft, and that should mean that his movements would be traceable. It was a comforting thought, and one of the few the Hunter was to have for some time to come.

It remained to learn the location of the island, as a preliminary step to getting back to it Bob received frequent letters from his parents, but for some time the Hunter did not recognize these as clues, partly because he had a good deal of trouble reading script and partly because he did not know the relationship of the boy to the senders of the letters. He had no particular scruples about reading the boy's mail, of course; he simply found it difficult. Robert did write to his parents as well, at somewhat irregular intervals, but they were not his only correspondents, and it was not until nearly the end of January that the Hunter found that by far the greater number of the boy's letters were going to and coming from one particular address.

The discovery was helped by the youngster's receipt of a typewriter as a Christmas present Whether his parents meant this as a gentle hint is hard to say, but at least it greatly facilitated the Hunter's reading of the outgoing mail, and he quickly learned that most letters went to Mr. and Mrs. Arthur Ki

He still did not know where it was, or how to get there; he could only be sure, from the duration of his airplane ride, that it was a long way from his present location. Bob would presumably be going back at the time of the next vacation, but that gave the fugitive another five months to get under cover-as if the five he had already enjoyed were not enough.

There was a large globular map of the planet in the school library and almost a plethora of flat maps and charts on the walls and in the various books in the school. Robert's persistent failure to bestow more than a passing glance at any of them promised quickly to drive the Hunter mad; and the alien, as time went on, was tempted more and more strongly to attempt to overcome the comparatively tiny muscles controlling the direction of his host's eyes. It was a bad and dangerous idea, but being intelligent does not mean that one's emotions are any the less powerful, as many men have demonstrated.

He controlled himself, therefore-partially. At least he controlled his actions; but as his patience wore ever thi

With the beings who normally served the Hunter's kind as hosts, communication eventually reached a high level of speed and comprehensiveness. The union took place with the host's full knowledge and consent; it was understood that the larger being furnished food, mobility, and muscular strength, while the other protected him from disease and injury as far as possible. Both brought highly intelligent minds into the partnership, and the relationship was one of extreme friendliness and close companionship in nearly all cases. With this understood by both parties, literally anything the symbiote did to affect his host's sensory organs could be utilized as a means of speech; and as a rule, over a period of years, multitudes of signals imperceptible to anyone else but perfectly clear to the two companions would develop to bring their speed of conversation to almost telepathic levels. The symbiote could administer twinges to any and all muscles, build shadow images directly on the retina of his host's eye, move the fur with which the other race was thickly covered-there was no limit to the various means of signaling.

Of course Bob did not have this background, but it was still possible to affect his senses. The Hunter dimly realized that there might be some emotional disturbance when the boy first learned of his presence, but he was sure he could minimize that. His own race had practiced symbiosis for so long that they had practically forgotten the problems incident to establishing the relationship with a being not accustomed to the idea. All that the Hunter really thought about, once he had made up his mind to communicate, was the apparent fact that circumstances were playing into his hands.

There was the "protective" net he had constructed over Bob's muscles; and there was the typewriter. The net could be contracted, like the muscles it covered, though with far less power. If a time arrived when Bob was sitting at the typewriter without particular plans of his own, it might be possible for the Hunter to strike a few keys in his own interest. The chances of success for the experiment depended largely on the boy's reaction when he found his fingers moving without orders; the Hunter managed to make himself feel optimistic about that.

Chapter IV. SIGNAL

Two nights after the Hunter made his decision to act the opportunity occurred. It was a Saturday evening, and the school had won a hockey game that afternoon. Bob had come through it without injury, to the Hunter's surprise and relief, and had managed to cover himself with a certain amount of glory, and the combination of institutional and personal triumph proved sufficient stimulus to cause the boy to write to his parents. He went to his room immediately after supper-the other occupant was not in at the time-and pounded off a description of the day's events with very fair speed and accuracy. At no tune did he relax sufficiently to give an opportunity for control, in the alien's opinion; but with the letter finished and sealed, Robert suddenly remembered a composition which his English teacher had decreed should be turned in the following Monday. It was as foreign to his nature as to that of most other schoolboys to get his work done so early, but the typewriter was out, and the hockey game offered itself as a subject which he could treat with some enthusiasm. He inserted a fresh piece of paper in the machine, typed the standard heading of title, pupil's name, and date, and then paused to think.

The alien wasted no time whatever. He had long since decided on the wording of the first message. Its first letter lay directly under the boy's left middle finger, and the net of unhuman flesh about the appropriate muscle promptly tugged as hard as it could on the tendon controlling that finger. The finger bent downward obediently and contacted the desired key, which descended-halfway. The pull was not powerful enough to lift the type bar from its felt rest. The Hunter knew he was weak compared to human muscles but had not realized he was that weak; Bob's manipulation of the keys had seemed so completely effortless. He sent more of his flesh flowing into the net which was trying to do the work of a small muscle and tried again-and again and again. The result was the same: the key descended far enough to take up the slack in its linkage, and stopped.

All this had attracted Bob's attention. He had, of course, experienced the quivering of muscles abruptly released from a heavy load, but there had been no load here. He pulled the offending hand away from the keyboard, and the suddenly frantic Hunter promptly transferred his attention to the other. As with a human being his control, poor enough in the begi