I was lying on my back, with Rheya's head resting on my shoulder.

The darkness was peopled now. I could hear footsteps. Something was piling up above me,higher and higher, infinitely high. The night transfixed me; the night took possession of me,enveloped and penetrated me, impalpable, insubstantial. Turned to stone, I had ceasedbreathing, there was no air to breathe. As though from a distance, I heard the beating of myheart. I summoned up all my remaining strength, straining every nerve, and waited for death. Iwent on waiting…I seemed to be growing smaller, and the invisible sky, horizonless, theformless immensity of space, without clouds, without stars, receded, extended and grew biggerall round me. I tried to crawl out of bed, but there was no bed; beneath the cover of darknessthere was a void. I pressed my hands to my face. I no longer had any fingers or any hands. Iwanted to scream…The room floated in a blue penumbra, which outlined the furniture and the laden bookshelves,and drained everything of color. A pearly whiteness flooded the window.

I was drenched with sweat. I glanced to one side. Rheya was gazing at me.

She raised her head.

"Has your arm gone to sleep?"Her eyes too had been drained of color; they were grey, but luminous, beneath the black lashes.

"What?" Her murmured words had seemed like a caress even before I understood theirmeaning. "No. Ah, yes!" I said, at last.

I put my hand on her shoulder; I had pins and needles in my fingers.

"Did you have a bad dream?" she asked.

I drew her to me with my other hand.

"A dream? Yes, I was dreaming. And you, didn't you sleep?""I don't know. I don't think so. I'm sleepy. But that mustn't stop you from sleeping…Why areyou looking at me like that?"I closed my eyes. Her heart was beating against mine. Her heart? A mere appendage, I toldmyself. But nothing surprised me any longer, not even my own indifference. I had crossed thefrontiers of fear and despair. I had come a long way—further than anyone had ever comebefore.

I raised myself on my elbow. Daybreak…and the peace that comes with dawn? A silent stormhad set the cloudless horizon ablaze. A streak of light, the first ray of the blue sun, penetratedthe room and broke up into sharp-edged reflections; there was a crossfire of sparks, whichcoruscated off the mirror, the door handles, the nickel pipes. The light scattered, falling on toevery smooth surface as though it wanted to conquer ever more space, to set the room alight. Ilooked at Rheya; the pupils of her grey eyes had contracted.

She asked in an expressionless voice, "Is the night over already?""Night never lasts long here.""And us?""What about us?""Are we going to stay here long?"Coming from her, the question had its comic side; but when I spoke, my voice held no trace ofgaiety.

"Quite a long time, probably. Why, don't you want to stay here?"Her eyes did not blink. She was looking at me inquiringly. Did I see her blink? I was not sure.

She drew back the blanket and I saw the little pink scar on her arm.

"Why are you looking at me like that?""Because you're very beautiful."She smiled, without a trace of mischief, modestly acknowledging my compliment.

"Really? It's as though…as though…""What?""As though you were doubtful of something.""What nonsense!""As though you didn't trust me and I were hiding something from you…""Rubbish!""By the way you're denying it, I can tell I'm right."The light became blinding. Shading my eyes with my hand, I looked for my dark glasses. Theywere on the table. When I was back by her side, Rheya smiled.

"What about me?"It took me a minute to understand what she meant.

"Dark glasses?"I got up and began to hunt through drawers and shelves, pushing aside books and instruments. Ifound two pairs of glasses, which I gave to Rheya. They were too big; they fell half way downher nose.

The shutters slid over the window; it was dark once more. Groping, I helped Rheya remove herglasses and put both pairs down under the bed.

"What shall we do now?" she asked.

"At night-time, one sleeps!""Kris…""Yes?""Do you want a compress for your forehead?""No, thanks. Thank you…my darling."I don't know why I had added those two words. In the darkness, I took her by her gracefulshoulders. I felt them tremble, and I knew, without the least shadow of doubt, that I held Rheyain my arms. Or rather, I understood in that moment that she was not trying to deceive me; itwas I who was deceiving her, since she sincerely believed herself to be Rheya.

I dropped off several times after that, and each time an anguished start jolted me awake.

Panting, exhausted, I pressed myself closer to her; my heart gradually growing calmer. Shetouched me cautiously on the cheeks and forehead with the tips of her fingers, to see whetheror not I was feverish. It was Rheya, the real Rheya, the one and only Rheya.

A change came over me; I ceased to struggle and almost at once I fell asleep.

I was awakened by an agreeable sensation of coolness. My face was covered by a damp cloth. Ipulled it off and found Rheya leaning over me. She was smiling and squeezing out a secondcloth over a bowl.

"What a sleep!" she said, laying another compress on my forehead. "Are you ill?""No."I wrinkled my forehead; the skin was supple once again. Rheya sat on the edge of my bed, herblack hair brushed back over the collar of a bathrobe—a man's bathrobe, with orange and blackstripes, the sleeves turned back to the elbow.

I was terribly hungry; it was at least twenty hours since my last meal. When Rheya hadfinished her ministrations I got up. Two dresses, draped over the back of a chair caught my eye—two absolutely identical white dresses, each decorated with a row of red buttons. I myselfhad helped Rheya out of one of them, and she had reappeared, yesterday evening, dressed inthe second. She followed my glance.

"I had to cut the seam open with scissors," she said. "I think the zip fastener must have gotstuck."The sight of the two identical dresses filled me with a horror which exceeded anything I hadfelt hitherto. Rheya was busy tidying up the medicine chest. I turned my back and bit myknuckles. Unable to take my eyes off the two dresses—or rather the original dress and itsdouble—I backed towards the door. The basin tap was running noisily. I opened the door and,slipping out of the room, cautiously closed it behind me. I heard the sound of running water,the clinking of bottles; then, suddenly, all sound ceased. I waited, my jaw clenched, my handsgripping the door handle, but with little hope of holding it shut. It was nearly torn from mygrasp by a savage jerk. But the door did not open; it shook and vibrated from top to bottom.

Dazed, I let go of the handle and stepped back. The panel, made of some plastic material,caved in as though an invisible person at my side had tried to break into the room. The steelframe bent further and further inwards and the paint was cracking. Suddenly I understood:

instead of pushing the door, which opened outwards, Rheya was trying to open it by pulling ittowards her. The reflection of the lighting strip in the ceiling was distorted in the white-painteddoor-panel; there was a resounding crack and the panel, forced beyond its limits, gave way.

Simultaneously the handle vanished, torn from its mounting. Two bloodstained handsappeared, thrusting through the opening and smearing the white paint with blood. The doorsplit in two, the broken halves hanging askew on their hinges. First a face appeared, deathlypale, then a wild-looking apparition, dressed in an orange and black bathrobe, flung itselfsobbing upon my chest.

I wanted to escape, but it was too late, and I was rooted to the spot. Rheya was breathingconvulsively, her dishevelled head drumming against my chest. Before I could put my armsround her to hold her up, Rheya collapsed.

Avoiding the ragged edges of the broken panel, I carried her into the room and laid her on thebed. Her fingertips were grazed and the nails torn. When her hands turned upwards, I saw thatthe palms were cut to the bone. I examined her face; her glazed eyes showed no sign ofrecognition.

"Rheya."The only answer was an inarticulate groan.

I went over to the medicine chest. The bed creaked; I turned round; Rheya was sitting up,looking at her bleeding hands with astonishment.

"Kris," she sobbed, "I…I…what happened to me?""You hurt yourself trying to break down the door," I answered curtly.

My lips were twitching convulsively, and I had to bite the lower one to keep it under control.

Rheya's glance took in the pieces of door-panel hanging from the steel frame, then she turnedher eyes back towards me. She was doing her best to hide her terror, but I could see her chintrembling.

I cut off some squares of gauze, picked up a pot of antiseptic powder and returned to thebedside. The glass jar slipped through my hands and shattered—but I no longer needed it.

I lifted one of Rheya's hands. The nails, still surrounded by traces of clotted blood, hadregrown. There was a pink scar in the hollow of her palm, but even this scar was healing,disappearing in front of my eyes.

I sat beside her and stroked her face, trying to smile without much success.

"What did you do that for, Rheya?""I did…that?"With her eyes, she indicated the door.

"Yes…Don't you remember?""No…that is, I saw you weren't there, I was very frightened, and…""And what?""I looked for you. I thought that perhaps you were in the bathroom…"Only then did I notice that the sliding door covering the entrance to the bathroom had beenpushed back.

"And then?""I ran to the door.""And after that?""I can't remember…Something must have happened…""What?""I don't know.""What do you remember?""I was sitting here, on the bed."She swung her legs over the edge of the bed, got up and went over to the shattered door.

"Kris!"Walking up behind her, I took her by the shoulders; she was shaking. She suddenly turned andwhispered:

"Kris, Kris…""Calm yourself!""Kris, if it's me…Kris, am I an epileptic?""What an extraordinary idea, my sweet. The doors in this place are rather special…"We left the room as the shutter was grinding its way up the window; the blue sun was sinkinginto the ocean.

I guided Rheya to the small kitchen on the other side of the dome. Together we raided thecupboards and the refrigerators. I soon noticed that Rheya was scarcely better than I was atcooking or even at opening tins. I devoured the contents of two tins and drank innumerablecups of coffee. Rheya also ate, but as children eat when they are not hungry and do not want todisplease their parents; on the other hand, she was not forcing herself, simply taking innourishment automatically, indifferently.

After our meal, we went into the sick bay, next to the radio-cabin. I had had an idea. I toldRheya that I wanted to give her a medical examination—a straightforward check-up—sat herin a mechanical chair, and took a syringe and some needles out of the sterilizer. I knew exactlywhere each object was to be found; as far as the model of the Station's interior was concerned,the instructors had not overlooked a single detail during my training course. Rheya held out herfingers; I took a sample of blood. I smeared the blood on to a slide which I laid in the suctionpipe, introduced it into the vacuum tank and bombarded it with silver ions.

Performing a familiar task had a soothing effect, and I felt better. Rheya, leaning back on thecushions in the mechanical chair, gazed around at the instruments in the sick bay.

The buzzing of the videophone broke the silence; I lifted the receiver:

"Kelvin."I looked at Rheya; she was still quiet, apparently exhausted by her recent efforts.

I heard a sigh of relief.

"At last."It was Snow. I waited, the receiver pressed close to my ear.

"You've had a visit, haven't you?""Yes.""Are you busy?""Yes.""A little auscultation, eh?""I suppose you've got a better suggestion—a game of chess maybe?""Don't be so touchy, Kelvin! Sartorius wants to meet you, he wants all three of us to meet.""Very kind of him!" I answered, taken aback. "But…" I stopped, then went on: "Is he alone?""No. I haven't explained properly. He wants to have a talk with us. We'll set up a three-wayvideophone link, but with the telescreen lenses covered.""I see. Why didn't he contact me himself? Is he frightened of me?""Quite possibly," grunted Snow. "What do you say?""A conference. In an hour's time. Will that suit you?""That's fine."I could see him on the screen—just his face, about the size of a fist. For a moment, he looked atme attentively; I could hear the crackling of the electric current. Then he said, hesitantly:

"Are you getting on all right?""Not too bad. How about you?""Not so well as you, I dare say. May I…?""Do you want to come over here?"I glanced at Rheya over my shoulder. She was leaning back, legs crossed, her head bent. Witha morose air, she was fiddling mechanically with the little chrome ball on the end of a chainfixed to the arm-rest.

Snow's voice erupted:

"Stop that, do you hear? I told you to stop it!"I could see his profile on the screen, but I could no longer hear him although his lips weremoving—he had put his hand over the microphone.

"No, I can't come," he said quickly. "Later perhaps, in any case, I'll contact you in an hour."The screen went blank; I replaced the receiver.

"Who was it?" asked Rheya indifferently.

"Snow, a cybernetician. You don't know him.""Is this going on much longer?""Are you bored?"I put the first of the series of slides into the neutron microscope, and, one after another, Ipressed the different-colored switches; the magnetic fields rumbled hollowly.

"There's not much to do in here, and if my humble company isn't enough for you…"I was talking distractedly, with long gaps between my words.

I pulled the big black hood round the eye-piece of the microscope towards me, and leaned myforehead against the resilient foam-rubber viewer. I could hear Rheya's voice, but withouttaking in what she was saying. Beneath my gaze, sharply foreshortened, was a vast desertflooded with silvery light, and strewn with rounded boulders—red corpuscles—which trembledand wriggled behind a veil of mist. I focused the eye-piece and penetrated further into thedepths of the silvery landscape. Without taking my eyes away from the viewer, I turned theview-finder; when a boulder, a single corpuscle, detached itself and appeared at the junction ofthe cross-hairs, I enlarged the image. The lens had apparently picked up a deformederythrocyte, sunken in the centre, whose uneven edges projected sharp shadows over the depthsof a circular crater. The crater, bristling with silver ion deposits, extended beyond themicroscope's field of vision. The nebulous outlines of threads of albumen, distorted andatrophied, appeared in the midst of an opalescent liquid. A worm of albumen twisted andturned beneath the cross-hairs of the lens. Gradually I increased the enlargement. At anymoment, I should reach the limit of this exploration of the depths; the shadow of a moleculeoccupied the whole of the space; then the image became fuzzy.

There was nothing to be seen. There should have been the ferment of a quivering cloud ofatoms, but I saw nothing. A dazzling light filled the screen, which was flawlessly clear. Ipushed the lever to its utmost. The angry, whirring noise grew louder, but the screen remaineda blank. An alarm signal sounded once, then was repeated; the circuit was overloaded. I took afinal look at the silvery desert, then I cut the current.

I looked at Rheya. She was in the middle of a yawn which she changed adroitly into a smile.

"Am I in good health?" she asked.

"Excellent. Couldn't be better." I continued to look at her and once more I felt as thoughsomething was crawling along my lower lip. What had happened exactly? What was themeaning of it? Was this body, frail and weak in appearance but indestructible in reality,actually made of nothing? I gave the microscope cylinder a blow with my fist. Was theinstrument out of order? No, I knew that it was working perfectly. I had followed the procedurefaithfully: first the cells, then the albumen, then the molecules; and everything was just as Iwas accustomed to seeing it in the course of examining thousands of slides. But the final step,into the heart of the matter, had taken me nowhere.

I put a ligature on Rheya, took some blood from a median vein and transferred it to a graduatedglass, then divided it between several test-tubes and began the analyses. These took longer thanusual; I was rather out of practice. The reactions were normal, every one of them.

I dropped some congealed acid on to a coral-tinted pearl. Smoke. The blood turned grey and adirty foam rose to the surface. Disintegration, decomposition, faster and faster! I turned myback to get another test-tube; when I looked again at the experiment, I nearly dropped the slimglass phial.

Beneath the skin of dirty foam, a dark coral was rising. The blood, destroyed by the acid, wasre-creating itself. It was crazy, impossible!

"Kris." I heard my name called, as though from a great distance. "Kris, the videophone!""What? Oh, thanks."The instrument had been buzzing for some time, but I had only just noticed it. I picked up thereceiver: "Kelvin.""Snow. We are now all three plugged into the same circuit."The high-pitched voice of Sartorius came over the receiver:

"Greetings, Dr. Kelvin!" It was the wary tone of voice, full of false assurance, of the lecturerwho knows he is on tenuous ground.

"Good-day to you, Dr. Sartorius!" I wanted to laugh; but in the circumstances I hardly felt Icould yield to a mood of hilarity. After all, which of us was the laughing stock? In my hand Iheld a test-tube containing some blood. I shook it. The blood coagulated. Had I been the victimof an illusion a moment ago? Had I, perhaps, been mistaken?

"I should like to set forth, gentlemen, certain questions concerning the…the phantoms."I listened to Sartorius, but my mind refused to take in his words. I was pondering thecoagulated blood and shutting out this distracting voice.

"Let's call them Phi-creatures," Snow interjected.

"Very well, agreed."A vertical line, bisecting the screen and barely perceptible, showed that I was linked by twochannels: on either side of this line, I should have seen two images—Snow and Sartorius. Butthe light-rimmed screen remained dark. Both my interlocutors had covered the lenses of theirsets.

"Each of us has made various experiments." The nasal voice still held the same wariness. Therewas a pause.

"I suggest first of all that we pool such knowledge as we have acquired so far," Sartorius wenton. "Afterwards, I shall venture to communicate to you the conclusion that I, personally, havereached. If you would be so good as to begin, Dr. Kelvin…""Me?"All of a sudden, I sensed Rheya watching me. I put my hand on the table and rolled the test-tube under the instrument racks. Then I perched myself on a stool which I dragged up with myfoot. I was about to decline to give an opinion when, to my surprise, I heard myself answer:

"Right. A little talk? I haven't done much, but I can tell you about it. A histological sample…certain reactions. Micro-reactions. I have the impression that…" I did not know how to go on.

Suddenly I found my tongue and continued: "Everything looks normal, but it's a camouflage. Acover. In a way, it's a super-copy, a reproduction which is superior to the original. I'll explainwhat I mean: there exists, in man, an absolute limit—a term to structural divisibility—whereashere, the frontiers have been pushed back. We are dealing with a sub-atomic structure.""Just a minute, just a minute! Kindly be more precise!" Sartorius interrupted.

Snow said nothing. Did I catch an echo of his rapid breathing? Rheya was looking at me again.

I realized that, in my excitement, I had almost shouted the last words. Calmer, I settled myselfon my uncomfortable perch and closed my eyes. How could I be more precise?

"The atom is the ultimate constituent element of our bodies. My guess is that the Phi-beings areconstituted of units smaller than ordinary atoms, much smaller.""Mesons," put in Sartorius. He did not sound in the least surprised.

"No, not mesons…I would have seen them. The power of this instrument here is between a10th to a 20th of an angstrom, isn't it? But nothing is visible, nothing whatsoever. So it can't bemesons. More likely neutrinos.""How do you account for that theory? Conglomerations of neutrinos are unstable…""I don't know. I'm not a physicist. Perhaps a magnetic field could stabilize them. It's not myprovince. In any event, if my observations are correct, the structure is made up of particles atleast ten thousand times smaller than atoms. Wait a minute, I haven't finished! If thealbuminous molecules and the cells were directly constructed from micro-atoms, they would beproportionally even smaller. This applies to the corpuscles, the micro-organisms, everything.

Now, the dimensions are those of atomic structures. Consequently, the albumen, the cell andthe nucleus of the cell are nothing but camouflage. The real structure, which determines thefunctions of the visitor, remains concealed.""Kelvin!"Snow had uttered a stifled cry. I stopped, horrified. I had said "visitor."Rheya had not overheard. At any rate, she had not understood. Her head in her hand, she wasstaring out of the window, her delicate profile etched against the purple dawn.

My distant interlocutors were silent; I could hear their breathing.

"There's something in what he says," Snow muttered.

"Yes," remarked Sartorius, "but for one fact: Kelvin's hypothetical particles have nothing to dowith the structure of the ocean. The ocean is composed of atoms.""Perhaps it's capable of producing neutrinos," I replied.

Suddenly I was bored with all their talk. The conversation was pointless, and not evenamusing.

"Kelvin's hypothesis explains this extraordinary resistance and the speed of regeneration,"Snow growled. "They probably carry their own energy source as well; they don't need food…""I believe I have the chair," Sartorius interrupted. The self-designated chairman of the debatewas clinging exasperatingly to his role. "I should like to raise the question of the motivationbehind the appearance of the Phi-creatures. I put it to you as follows: what are the Phi-creatures? They are not autonomous individuals, nor copies of actual persons. They are merelyprojections materializing from our brains, based on a given individual."I was struck by the soundness of this description; Sartorius might not be very sympathetic, buthe was certainly no fool.

I rejoined the conversation:

"I think you're right. Your definition explains why a particular per…creation appears ratherthan another. The origin of the materialization lies in the most durable imprints of memory,those which are especially well-defined, but no single imprint can be completely isolated, andin the course of the reproduction, fragments of related imprints are absorbed. Thus the newarrival sometimes reveals a more extensive knowledge than that of the individual of whom it isa copy…""Kelvin!" shouted Snow once more.

It was only Snow who reacted to my lapses; Sartorius did not seem to be affected by them. Didthis mean that Sartorius's visitor was less perspicacious than Snow's? For a moment, Iimagined the scholarly Sartorius cohabiting with a cretinous dwarf.

"Indeed, that corresponds with our observations," Sartorius said. "Now, let us consider themotivation behind the apparition! It is natural enough to assume, in the first instance, that weare the object of an experiment. When I examine this proposition, the experiment seems to mebadly designed. When we carry out an experiment, we profit by the results and, above all, wecarefully note the defects of our methods. As a result, we introduce modifications in our futureprocedure. But, in the case with which we are concerned, not a single modification hasoccurred. The Phi-creatures reappear exactly as they were, down to the last detail…asvulnerable as before, each time we attempt to…to rid ourselves of them…""Exactly," I broke in, "a recoil, with no compensating mechanism, as Dr. Snow would say.

Conclusions?""Simply that the thesis of experimentation is inconsistent with this…this unbelievablebungling. The ocean is…precise. The dual-level structure of the Phi-creatures testifies to thisprecision. Within the prescribed limits, the Phi-creatures behave in the same way as the real…the…er…"He could not disentangle himself.

"The originals," said Snow, in a loud whisper.

"Yes, the originals. But when the situation no longer corresponds to the normal faculties of…er…the original, the Phi-creature suffers a sort of 'disconnection of consciousness,' followedimmediately by unusual, non-human manifestations…""It's true," I said, "and we can amuse ourselves drawing up a catalogue of the behavior of…ofthese creatures—a totally frivolous occupation!""I'm not sure of that," protested Sartorius. I suddenly realized why he irritated me so much: hedidn't talk, he lectured, as though he were in the chair at the Institute. He seemed to beincapable of expressing himself in any other way. "Here we come to the question ofindividuality," he went on, "of which, I am quite sure, the ocean has not the smallest inkling. Ithink that the…er…delicate or shocking aspect of our present situation is completely beyondits comprehension.""You think its activities are unpremeditated?"I was somewhat bewildered by Sartorius's point of view, but on second thought, I realized thatit could not be dismissed.

"No, unlike our colleague Snow, I don't believe there is malice, or deliberate cruelty…"Snow broke in:

"I'm not suggesting it has human feelings, I'm merely trying to find an explanation for thesecontinual reappearances."With a secret desire to nag poor Sartorius, I said:

"Perhaps they are plugged into a contrivance which goes round and round, endlessly repeatingitself, like a gramophone record…""Gentlemen, I beg you, let us not waste time! I haven't yet finished. In normal circumstances, Iwould have felt it premature to present a report, even a provisional one, on the progress of myresearch; in view of the prevailing situation, however, I think I may allow myself to speak out.

I have the impression—only an impression, mark you—that Dr. Kelvin's hypothesis is notwithout validity. I am alluding to the hypothesis of a neutrino structure…Our knowledge in thisfield is purely theoretical. We did not know if there was any possibility of stabilizing suchstructures. Now a clearly defined solution offers itself to us. A means of neutralizing themagnetic field that maintains the stability of the structure…"A few moments previously, I had noticed that the screen was flickering with light. Now a splitappeared from top to bottom of the left-hand side. I saw something pink move slowly out ofview. Then the lens-cover slipped again, disclosing the screen.

Sartorius gave an anguished cry:

"Go away! Go away!"I saw his hands flapping and struggling, then his forearms, covered by the wide sleeves of thelaboratory gown. A bright golden disc shone out for an instant, then everything went dark.

Only then did I realize that this golden disc was a straw hat…I took a deep breath.

"Snow?"An exhausted voice replied:

"Yes, Kelvin…" Hearing his voice, I realized that I had become quite fond of him, and that Ipreferred not to know who or what his companion was. "That's enough for now, don't youthink?" he said.

"I agree." Before he could cut off, I added quickly: "Listen, if you can, come and see me, eitherin the operating room or in my cabin.""OK, but I don't know when."The conference was over.