“Right.”

  “And get them to sign telepathy releases. I’ll give them a preliminary mind-probe this evening after I’ve had a chance to study the clinical findings. Maintain absolute quarantine, of course. This thing might just be infectious. Play it very safe.”

  Nakadai nodded. Mookherji flashed a professional smile at the six somber spacemen and went out, brooding. A nightmare virus? Or a mind-meddling alien organism that no one can see? He wasn’t sure which notion he liked less. Probably, though, there was some prosaic and unstartling explanation for that month of bad dreams—contaminated food supplies, or something funny in the atmosphere recycler. A simple, mundane explanation.

  Probably.

  ***

  THE FIRST TIME IT HAPPENED, the Vsiir was not sure what had actually taken place. It had touched a human mind; there had been an immediate vehement reaction; the Vsiir had pulled back, alarmed by the surging fury of the response, and then, a moment later, had been unable to locate the mind at all. Possibly it was some defense mechanism, the Vsiir thought, by which the humans guarded their minds against intruders. But that seemed unlikely since the humans’ minds were quite effectively guarded most of the time anyway. Aboard the ship, whenever the Vsiir had managed to slip past the walls that shielded the minds of the crewmen, it had always encountered a great deal of turbulence—plainly these humans did not enjoy mental contact with a Vsiir—but never this complete shutdown, this total cutoff of signal. Puzzled, the Vsiir tried again, reaching toward an open mind situated not far from where the one that had vanished had been. Kindly attention, a moment of consideration for confused other-worldly individual, victim of unhappy circumstances, who—

  Again the violent response: a sudden tremendous flare of mental energy, a churning blaze of fear and pain and shock. And again, moments later, complete silence, as though the human had retreated behind an impermeable barrier. Where are you? Where did you go? The Vsiir, troubled, took the risk of creating an optical receptor that worked in the visible spectrum—and that therefore would itself be visible to humans—and surveyed the scene. It saw a human on a bed, completely surrounded by intricate machinery. Colored lights were flashing. Other humans, looking agitated, were rushing toward the bed. The human on the bed lay quite still, not even moving when a metal arm descended and jabbed a long bright needle into his chest.

  Suddenly the Vsiir understood.

  The two humans must have experienced termination of existence!

  Hastily the Vsiir dissolved its visible-spectrum receptor and retreated to a sheltered corner to consider what had happened. Datum: two humans had died. Datum: each had undergone termination immediately after receiving a mental transmission from the Vsiir. Problem: had the mental transmission brought about the terminations?

  The possibility that the Vsiir might have destroyed two lives was shocking and appalling, and such a chill went through its body that it shrank into a tight, hard ball, with all thought-processes snarled. It needed several minutes to return to a fully functional state. If its attempts at communicating with these humans produced such terrible effects, the Vsiir realized, then its prospects of finding help on this planet were slim. How could it dare risk trying to contact other humans, if—

  A comforting thought surfaced. The Vsiir realized that it was jumping to a hasty conclusion on the basis of sketchy evidence, while overlooking some powerful arguments against that conclusion. All during the voyage to this world the Vsiir had been making contact with humans, the six crewmen, and none of them had terminated. That was ample evidence that humans could withstand contact with a Vsiir mind. Therefore contact alone could not have caused these two deaths.

  Possibly it was only coincidental that the Vsiir had approached two humans in succession that were on the verge of termination. Was this the place where humans were brought when their time of termination was near? Would the terminations have happened even if the Vsiir had not tried to make contact? Was the attempt at contact just enough of a drain on dwindling energies to push the two over the edge into termination? The Vsiir did not know. It was uncomfortably conscious of how many important facts it lacked. Only one thing was certain: its time was running short. If it did not find help soon, metabolic decay was going to set in, followed by metamorphic rigidity, followed by a fatal loss in adaptability, followed by . . . termination.

  The Vsiir had no choice. Continuing its quest for contact with a human was its only hope of survival. Cautiously, timidly, the Vsiir again began to send out its probes, looking for a properly receptive mind. This one was walled. So was this. And all these: no entrance, no entrance! The Vsiir wondered if the barriers these humans possessed were designed merely to keep out intruding nonhuman consciousnesses, or actually shielded each human against mental contact of all kinds, including contact with other humans. If any human-to-human contact existed, the Vsiir had not detected it, either in this building or aboard the spaceship. What a strange race!

  Perhaps it would be best to try a different level of this building. The Vsiir flowed easily under a closed door and up a service staircase to a higher floor. Once more it sent forth its probes. A closed mind here. And here. And here. And then a receptive one. The Vsiir prepared to send its message. For safety’s sake it stepped down the power of its transmission, letting a mere wisp of thought curl forth. Do you hear? Stranded extraterrestrial being is calling. Seeks aid. Wishes—

  From the human came a sharp, stinging displeasure-response, wordless but unmistakably hostile. The Vsiir at once withdrew. It waited, terrified, fearing that it had caused another termination. No: the human mind continued to function, although it was no longer open, but now surrounded by the sort of barrier humans normally wore. Drooping, dejected, the Vsiir crept away. Failure, again. Not even a moment of meaningful mind-to-mind contact. Was there no way to reach these people? Dismally, the Vsiir resumed its search for a receptive mind. What else could it do?

  ***

  THE VISIT TO THE QUARANTINE building had taken forty minutes out of Dr. Mookherji’s morning schedule. That bothered him. He couldn’t blame the quarantine people for getting upset over the six spacemen’s tale of chronic hallucinations, but he didn’t think the situation, mysterious as it was, was grave enough to warrant calling him in on an emergency basis. Whatever was troubling the spacemen would eventually come to light; meanwhile they were safely isolated from the rest of the starport. Nakadai should have run more tests before asking him. And he resented having to steal time from his patients.

  But as he began his belated morning rounds, Mookherji calmed himself with a deliberate effort: it wouldn’t do him or his patients any good if he visited them while still loaded with tensions and irritations. He was supposed to be a healer, not a spreader of anxieties. He spent a moment going through a de-escalation routine, and by the time he entered the first patient’s room—that of Satina Ransom—he was convincingly relaxed and amiable.

  Satina lay on her left side, eyes closed, a slender girl of sixteen with a fragile-looking face and long, soft straw-colored hair. A spidery network of monitoring systems surrounded her. She had been unconscious for fourteen months, twelve of them here in the starport’s neuropathology ward and the last six under Mookherji’s care, As a holiday treat, her parents had taken her to one of the resorts on Titan during the best season for viewing Saturn’s rings; with great difficulty they succeeded in booking reservations at Galileo Dome, and were there on the grim day when a violent Titanquake ruptured the dome and exposed a thousand tourists to the icy moon’s poisonous methane atmosphere. Satina was one of the lucky ones: she got no more than a couple of whiffs of the stuff before a dome guide with whom she’d been talking managed to slap a breathing mask over her face. She survived. Her mother, father, and young brother didn’t. But she had never regained consciousness after collapsing at the moment of the disaster. Months of examination on Earth had shown that her brief methane inhalation hadn’t caused any major brain damage; organically there seemed to be nothing wrong with her, but she refused to wake up. A shock reaction, Mookherji believed: she would rather go on dreaming forever than return to the living nightmare that consciousness had become. He had been able to reach her mind telepathically, but so far he had been unable to cleanse her of the trauma of that catastrophe and bring her back to the waking world.

  Now he prepared to make contact. There was nothing easy or automatic about his telepathy; “reading” minds was strenuous work for him, as difficult and as taxing as running a cross-country race or memorizing a lengthy part in Hamlet. Despite the fears of laymen, he had no way of scanning anyone’s intimate thoughts with a casual glance. To enter another mind, he had to go through an elaborate procedure of warming up and reaching out, and even so it was a slow business to tune in on somebody’s “wavelength”, with little coherent information coming across until the ninth or tenth attempt. The gift had been in the Mookherji family for at least a dozen generations, helped along by shrewdly planned marriages designed to conserve the precious gene; he was more adept than any of his ancestors, yet it might take another century or two of Mookherjis to produce a really potent telepath. At least he was able to make good use of such talent for mind-contact as he had. He knew that many members of his family in earlier times had been forced to hide their gift from those about them, back in India, lest they be classed with vampires and werewolves and cast out of society.

  Gently he placed his dark hand on Satina’s pale wrist. Physical contact was necessary to attain the mental linkage. He concentrated on reaching her. After months of teletherapy, her mind was sensitized to his; he was able to skip the intermediate steps, and, once he was warmed up, could plunge straight into her troubled soul. His eyes were closed. He saw a swirl of pearly-gray fog before him: Satina’s mind. He thrust himself into it, entering easily. Up from the depths of her spirit swam a question mark.

  —Who is it? Doctor?

  —Me, yes. How are you today, Satina?

  —Fine. Just fine.

  —Been sleeping well?

  —It’s so peaceful here, doctor.

  —Yes. Yes, I imagine it is. But you ought to see how it is here. A wonderful summer day. The sun in the blue sky. Everything in bloom. A perfect day for swimming, eh? Wouldn’t you like a swim? He puts all the force of his concentration into images of swimming: a cold mountain stream, a deep pool at the base of a creamy waterfall, the sudden delightful shock of diving in, the crystal flow tingling against her warm skin, the laughter of her friends, the splashing, the swift powerful strokes carrying her to the far shore—

  —I’d rather stay where I am, she tells him.

  —Maybe you’d like to go floating instead? He summons the sensations of free flight: a floater-node fastened to her belt, lifting her serenely to an altitude of a hundred feet, and off she goes, drifting over fields and valleys, her friends beside her, her body totally relaxed, weightless, soaring on the updrafts, rising until the ground is a checkerboard of brown and green, looking down on the tiny houses and the comical cars, now crossing a shimmering silvery lake, now hovering over a dark, somber forest of thick-packed spruce, now simply lying on her back, legs crossed, hands clasped behind her head, the sunlight on her cheeks, three hundred feet of nothingness underneath her—

  But Satina doesn’t take his bait. She prefers to stay where she is. The temptations of floating are not strong enough.

  Mookherji does not have enough energy left to try a third attempt at luring her out of her coma. Instead he shifts to a purely medical function and tries to probe for the source of the trauma that has cut her off from the world. The fright, no doubt; and the terrible crack in the dome, spelling the end to all security; and the sight of her parents and brother dying before her eyes; and the swampy reek of Titan’s atmosphere hitting her nostrils—all of those things, no doubt. But people have rebounded from worse calamities. Why does she insist on withdrawing from life? Why not come to terms with the dreadful past, and accept existence again?

  She fights him. Her defenses are fierce; she does not want him meddling with her mind. All of their sessions have ended this way: Satina clinging to her retreat, Satina blocking any shot at knocking her free of her self-imposed prison. He has gone on hoping that one day she will lower her guard. But this is not to be the day. Wearily, he pulls back from the core of her mind and talks to her on a shallower level.

  —You ought to be getting back to school, Satina.

  —Not yet. It’s been such a short vacation!

  —Do you know how long?

  —About three weeks, isn’t it?

  —Fourteen months so far, he tells her.

  —That’s impossible. We just went away to Titan a little while ago—the week before Christmas, wasn’t it, and—

  —Satina, how old are you?

  —I’ll be fifteen in April.

  —Wrong, he tells her. That April’s been here and so has the next one. You were sixteen two months ago. Sixteen, Satina.

  —That can’t be true, doctor. A girl’s sixteenth birthday is something special, don’t you know that? My parents are going to give me a big party. All my friends invited. And a nine piece robot orchestra with synthesizers. And I know that that hasn’t happened yet, so how can I be sixteen?

  His reservoir of strength is almost drained. His mental signal is weak. He cannot find the energy to tell her that she is blocking reality again, that her parents are dead, that time is passing while she lies here, that it is too late for a Sweet Sixteen party.

  —We’ll talk about it . . . another time, Satina. I’ll . . . see . . . you . . . again . . . tomorrow . . . Tomorrow . . . morning . . .

  —Don’t go so soon, doctor! But he can no longer hold the contact, and lets it break.

  Releasing her, Mookherji stood up, shaking his head. A shame, he thought. A damned shame. He went out of the room on trembling legs and paused a moment in the hall, propping himself against a closed door and mopping his sweaty forehead. He was getting nowhere with Satina. After the initial encouraging period of contact, he had failed entirely to lessen the intensity of her coma. She had settled quite comfortably into her delusive world of withdrawal, and, telepathy or no, he could find no way to blast her loose.

  He took a deep breath. Fighting back a growing mood of bleak discouragement, he went toward the next patient’s room.

  ***

  THE OPERATION WAS GOING SMOOTHLY. The dozen third-year medical students occupied the observation deck of the surgical gallery on the starport hospital’s third floor, studying Dr. Hammond’s expert technique by direct viewing and by simultaneous microamplified relay to their individual desk-screens. The patient, a brain-tumor victim in his late sixties, was visible only as a head and shoulders protruding from a life-support chamber. His scalp had been shaved; blue lines and dark red dots were painted on it to indicate the inner contours of the skull, as previously determined by short-range sonar bounces; the surgeon had finished the job of positioning the lasers that would excise the tumor. The hard part was over. Nothing remained except to bring the lasers to full power and send their fierce, precise bolts of light slicing into the patient’s brain. Cranial surgery of this kind was entirely bloodless; there was no need to cut through skin and bone to expose the tumor, for the beams of the lasers, calibrated to a millionth of a millimeter, would penetrate through minute openings and, playing on the tumor from different sides, destroy the malignant growth without harming a bit of the surrounding healthy brain tissue. Planning was everything in an operation like this. Once the exact outlines of the tumor were determined, and the surgical lasers were mounted at the correct angles, any intern could finish the job.

  For Dr. Hammond it was a routine procedure. He had performed a hundred operations of this kind in the past year alone. He gave the signal; the warning light glowed on the laser rack; the students in the gallery leaned forth expectantly—

  And, just as the lasers’ glittering fire leaped toward the operating table, the face of the anesthetized patient contorted weirdly, as though some terrifying dream had come drifting up out of the caverns of the man’s drugged mind. His nostrils flared; his lips drew back; his eyes opened wide; he seemed to be trying to scream; he moved convulsively, twisting his head to one side. The lasers bit deep the patient’s left temple, far from the indicated zone of the tumor. The right side of his face began to sag, all muscles paralyzed. The medical students looked at each other in bewilderment. Dr. Hammond, stunned, retained enough presence of mind to kill the lasers with a quick swipe of his hand. Then, gripping the operating table with both hands in his agitation, he peered at the dials and meters that told him the details of the botched operation. The tumor remained intact; a vast sector of the patient’s brain had been devastated. “Impossible,” Hammond muttered. What could goad a patient under anesthesia into jumping around like that? “Impossible. Impossible.” He strode to the end of the table and checked the readings on the life-support chamber. The question now was not whether the brain tumor would be successfully removed; the immediate question was whether the patient was going to survive.