While Langner began sorting out a shelf stacked with photographic plates, Pirx maneuvered around him and went to explore the rest of the station. To the left, branching off a tiny vestibule, stood the door to the kitchen; straight ahead was the hatch to the pressure chamber, with two other doors to the right, both leading to tiny cubicles. He opened the door to his room: bare except for a bed, a folding chair, a collapsible writing desk, and a few bookshelves. The ceiling dropped down over the bed at an angle, as in an attic, but it was curved instead of sloping, matching the station’s exterior design.
He made his way back to the vestibule. The chamber hatch, rounded at the corners and hermetically sealed by a thick rubberized silicone gasket, was mounted with a spoked wheel and a small lamp, which, when lit, meant that the outer hatch was open and there was a vacuum inside. The lamp was off at the moment. He opened the door, tripping two lights, which revealed a narrow compartment with sheer metal walls and a vertical iron-rung ladder in the center, the ladder leading up to a hatch in the ceiling. Under the first rung was a chalk outline, partially obliterated by footsteps: the place where Savage’s body had been discovered. The body had been lying with its legs tucked up and on its side, frozen to the rough concrete slab where the blood had escaped from his eyes and mouth.
Pirx studied the blurry outline for a while, then withdrew. As he was sealing the airtight door, his head suddenly snapped back: footfalls overhead. It was Langner, who had climbed the ladder mounted opposite the vestibule and was prowling about the observatory. Pirx poked his head up through a round opening in the floor and took stock of the hardware: a slip-covered telescope the size of a small cannon, astrographs, cameras, plus two other fair-size pieces of equipment—one a Wilson cloud chamber, the other a high-voltage spark-gap chamber, rigged with an attachment for photographing ionization trails.
The station was designed for monitoring cosmic radiation, and the photographic plates were everywhere. The orange packets containing them were sandwiched between books, stacked under shelves, stuffed into drawers, plopped on the floor beside beds, and even strewn about the kitchen.
That was all there was to the station, not counting the huge water and oxygen tanks stored underground, deep beneath the station’s floor in the Mendeleev massif.
Above each compartment was a CO2 gauge and a perforated air vent. The air-conditioning system silently took in air, purified it of carbon dioxide, added the right amount of oxygen, and forced the mixture back out into the cabins. Pirx welcomed every footstep, every thud coming from the observatory; the moment the noises stopped, the silence swelled to the point that he could hear the whispering murmur of his own blood, as clearly as he had that time in the “loony dip,” though the latter had one distinct advantage: you could quit at any time.
Langner came down from the observatory and started making supper, but so quietly and competently that everything was on the table by the time Pirx came in. “Pass the salt, please.” “Any bread left in the can?” “Tomorrow we’ll have to open a new one.” “Tea or coffee?” That was the extent of their table talk—which, at the present moment, suited Pirx just fine. What meal was this? Their third of the day? Fourth? Breakfast of the following day? Langner said he had some developing to do and scooted along upstairs. But Pirx was left with nothing to do.
Suddenly he understood. He had been sent up here for one reason only: to keep Langner company. Astrophysics? Cosmic radiation? That wasn’t his line. And Langner wasn’t about to break him in, either, by teaching him how to handle an astrograph. No, he was here because he had earned the highest grade in the class, because the psychologists said he wouldn’t go batty. So, fourteen nights and fourteen days in this sardine can, waiting for no one knew what, investigating no one knew what.
Suddenly the Mission, which only a while ago had seemed such a blessing, was showing him its true face: a blank. Protect Langner and himself? Okay, but from what? Hunt for clues? What clues? No one seriously believed that he, dumb clod that he was, would stumble onto something overlooked by a commission of lunar experts.
He went on sitting at the table. He knew there were dishes to be washed. That he would have to be stingy with the tap water—water, that precious commodity flown in in ice blocks and fired into the basin at the foot of the station on a two-and-a-half-kilometer parabola. They couldn’t afford to waste a drop of the wet stuff.
He knew all that and still didn’t budge. He couldn’t even muster the energy to lift his arm when it fell limply onto the edge of the table. His head was still reeling from the heat and the waste and the darkness and the silence that pressed on this steel shell from all sides. He rubbed his burning eyes that felt sand-whipped, stood up, and, feeling twice his normal weight, cleared the table and dumped the dirty dishes into the sink and started rinsing them with a trickle of warm water. And as he stood there scrubbing the dishes, turning them over in his hands, scraping off the little globs of fat, he smiled at his own dreams, which had been left behind somewhere on the trail leading up to the Mendeleev ridge, dreams that now seemed so distant in time and place, so absurdly inappropriate, that he did not even need to feel ashamed of them.
Langner never changed; whether you shared his company for a year or a day, he never altered his routine. He worked diligently, but always according to schedule, never hurrying. He was a man without any vices, eccentricities, or tics. Now, when you live with someone in such close quarters, the smallest trifle can begin to grate. Someone hogs the shower, or won’t open a can of spinach because he doesn’t like spinach, or grumps a lot, or starts sporting a prickly stubble, or shaves but pampers himself in front of the mirror… But Langner was not that sort. He ate everything, but without gusto. He never bellyached or sulked. When it was his turn to wash, he washed. When he was asked something, he replied. He was neither unsociable nor overbearing. And it was precisely this neutral, neither-here-nor-there behavior of his that began to get on Pirx’s nerves, because the first evening’s impression—when the image of the physicist fastidiously arranging his books on the shelf had seemed the embodiment of a quiet and unassuming heroism, of a truly enviable and noble-minded dedication—well, that impression had become tarnished, to say the least, to the point that his partner—his compulsory partner—now struck him as lackluster, even boring. Not that he actually was bored or irritated by Langner’s company. Because meanwhile he had found something else to occupy him—at least temporarily. Now that he was more at home in his surroundings, he began reviewing all the known facts in the case.
The avalanche had occurred when the station had been only four months in operation. Contrary to what one would have expected, it transpired not at dawn or dusk but in the middle of a lunar afternoon. Suddenly, with no advance warning, three-fourths of the overhanging wall known as the Eagle’s Wing had collapsed. By coincidence, that same day the station’s four-man crew had been mustered to receive a convoy of transports. They were all eyewitnesses to the tragedy.
Subsequent studies showed that the deep incisions on the Eagle’s main rib had indeed disturbed the crystal core and upset its tectonic equilibrium. The English shifted the burden of blame onto the Canadians, and the Canadians onto the English, their mutual loyalty being manifested only by their consistent failure to heed Professor Animtsev’s advice. The four crew members standing in front of the station, less than a mile from the scene of the accident, later described how the blinding wall had split in two, collapsing the system of wedges and barriers, how the avalanche swept away the road and spilled into the valley below, and how, for the next thirty hours, the basin had been a sea of undulating white. In the space of just a few minutes the flood of swirling debris had been carried by the slide’s momentum clear across to the other side of the crater.
Two transports had been within range of the avalanche. The one bringing up the rear of the column had been buried instantly by a ten-meter-thick layer of rubble. The other had already reached the upper road, was just out of range of the main flow, when an enormous mass of debris jumped the last of the barriers and swept the vehicle over the side of the three-hundred-meter cliff. At the last minute its driver managed to open the hatch and drop down onto the shifting scree. He became the disaster’s lone survivor, outliving his companions by only a few hours. For the witnesses those few hours became a living hell. The driver, a French-Canadian named Roget, who either remained conscious or regained consciousness later on, started radioing for help from somewhere inside the white cloud—his receiver had been damaged, but not his transmitter. There was no locating the injured man. The multiple refractions caused by the waves bouncing off the boulders—so mammoth the people moved in and out of the dusty labyrinth as through a city in ruins—made it impossible to get an accurate fix. Radar was out because of the iron sulfide content of the rock. An hour later, another avalanche, originating from up around the Gap, forced the men to call off their search. This second slide, though smaller than the first, portended still others. There was nothing to do but wait. And wait they did, all the while hearing Roget’s voice loud and clear at the station, the basin in which he was stranded acting as a dish reflector. Three hours later the Tsiolkovsky team arrived and drove out into the dust cloud with their ground crawlers, but the shifting talus kept tipping their vehicles on end—the reduced gravity made the angle of inclination commensurately greater on the lunar scree than Earthside. Rescue teams, dispatched into those areas not accessible to the crawlers, combed the rubble three times. One of the searchers fell into a crevasse; only his immediate transfer to Tsiolkovsky and prompt medical treatment saved his life. Despite this near-fatality, the search went on, prodded by the sound of Roget’s ever weaker but still audible voice.
Five hours later the voice fell silent, though they knew he was still alive. Every space suit had, in addition to a voice transmitter, a miniature automatic sensor hooked up to the respirator. The sensor relayed, electromagnetically, every breath to the station, where a special tracking device, similar to a “magic eye,” projected it as a luminous green butterfly-shaped blip, dilating and contracting in rhythm to the man’s respiration. The phosphorescent “butterfly” indicated that the unconscious Roget was still breathing. The pulsations grew steadily weaker, slower, but no one left the radio station. The people crowded inside waited, in helpless despair, for the inevitable.
Roget continued breathing for another two hours. Finally the green light on the magic eye flickered and shrank for good. The mutilated body was located some thirty hours later, stone-hard, so badly mangled that he was buried together with his aluminized space suit, as in a coffin.
Later a new road was staked out—the same rocky trail used by Pirx on his ascent to the station. The Canadians were all set to abandon the project, but their persistent English colleagues solved the logistical problem in a manner originally conceived during the assault on Mount Everest. It was rejected at the time as unworkable.
News of the accident circulated in numerous, often conflicting versions until the clamor finally subsided, to become a tragic chapter in the chronicle of man’s struggle with the lunar wilds. Meanwhile, astrophysicists on field assignment continued to take turns manning the station. Six lunar days and nights passed. Just when it seemed the sorely tested station had given rise to its last sensation, Mendeleev’s radio station failed to acknowledge Tsiolkovsky’s transmission at dawn. Again the Tsiolkovsky team set out on a rescue—or rather reconnaissance—mission. They arrived by ship, landing at the foot of the slide.
They reached the station when the crater floor was still untouched by the Sun’s rays. Except for the metal shell under the peak, glinting in the horizontal shaft of light, the entire basin was under a mantle of darkness. They found the outer hatch open, and down below, at the foot of the ladder, Savage’s body, slumped to the floor in a way that suggested he had slipped and fallen from the rungs. Death was attributed to asphyxiation, caused by a punctured faceplate. Faint traces of dust, later found lining the inside of his gloves, suggested that he had been returning to, not leaving, the station, though the traces could easily have remained from a previous climb. The body of the second Canadian, Challiers, was discovered only after a meticulous combing of the neighboring ravines and gullies. Rescuers lowered on three-hundred-meter ropes brought up the body from the base of the cliff, no more than fifty steps away from the place where Roget had expired.
No matter how they tried to reconstruct the sequence of events, not a single plausible hypothesis could be advanced. That’s when a combined English-Canadian commission decided to conduct an on-the-spot inquiry.
The inquiry disclosed that the hands of Challiers’s watch had stopped at exactly twelve o’clock—whether noon or midnight, it was impossible to say—and Savage’s at two. In the case of Savage, an expert’s examination of the watch’s works revealed that the mainspring had been fully wound; hence the time shown on the watch’s face did not necessarily coincide with the time of death.
Everything inside the station was found to be in perfect order. The log, recording only events of scientific relevance, contained nothing that could shed the faintest light on the unexplained fatalities. Pirx went through it carefully, entry by entry. They were written in the usual laconic style. Astrographic survey taken at such-and-such a time, so-and-so many plates exposed under such-and-such conditions… Not a single reference, however oblique, to whatever had transpired that night, Savage’s and Challiers’s last. Not only was the station found to be in perfect order, but all the evidence indicated that death had taken its inhabitants by surprise. An open book, with Challiers’s notes in the margin, was found lying face up, with another book on top to keep the pages from turning, under a burning lamp. A pipe, which had tipped over on its side and spilled a few cinders onto the table, lightly scorching the Bakelite top, lay beside it. Savage, from the looks of things, had been making supper. In the kitchen they found freshly opened cans, a mixing bowl full of omelet batter, and on the little white eating table, place settings for two and slices of stale bread.
The commission concluded that one of them had interrupted his reading, laying down his pipe in the manner of someone intending to be out of the room for only a few minutes. The other had walked off in the middle of preparing supper, leaving behind a greased frying pan and not even bothering to shut the refrigerator door. Two men had suited up and stepped out into a lunar night. Together? Separately? And, above all, why?
The two Canadians had been stationed at Mendeleev long enough—two weeks, to be exact—to know their way around. With sunrise only twelve or so hours away, the question naturally arose: Why hadn’t they waited until dawn, assuming their intent was to climb down to the crater floor? And in Challiers’s case, that was fairly safe to assume, going by the location of his body. But Challiers must have realized, as Savage must have, that it was an act of lunacy to go down the face of the mountain. The wall made a gradual and easy descent before falling off abruptly in the place where the avalanche had left a gaping hole. The new road bypassed the canyon, traveling a straight line along the route staked out by the aluminum markers. Everyone, even one-time visitors to the station, was aware of the danger. And yet here was one of its permanent staff members, a man who should have known better, attempting to navigate a sheer precipice. Why? A deliberate suicide? But would someone bent on committing suicide simply interrupt his reading, put aside his book and pipe, and go out to meet certain death?
And Savage. How to explain Savage’s punctured visor? Was he on his way into or out of the station? Had he gone out to look for Challiers when he failed to show up? Or had they left together? If that were so, how could he have let him go down the cliff?
There was no end to the unanswered questions.
The only item not in its proper place was a packet of photographic plates, the type used to record cosmic radiation. It was found lying on the kitchen table alongside two empty, spotlessly clean plates.
The commission postulated the following sequence of events. That day—the day of the accident—it was Challiers’s watch. Distracted by his reading, he suddenly noticed the time—eleven o’clock. Eleven was the time he was scheduled to restock the plates. The plates were exposed outside the station, a hundred paces up the slope, in a shaft tunneled in the rock—small and not too deep, with lead-lined walls to permit only the zenith rays to hit the plates. A routine exercise, one of the many performed at the station. Challiers, then, putting down his book and pipe, got up, grabbed a new packet of plates, suited up, and left the station through the pressure chamber. He went up to the shaft, climbed down the recessed ladder, switched the plates, and started back with the exposed ones.
On his way back, he made a detour. Subsequent examination of his space suit, severely damaged in the fall, disclosed no malfunction in his respirator unit, ruling out the possibility of a sudden loss of memory due to anoxia.
The members of the commission hypothesized that Challiers must have suffered a momentary blackout, reasoning that he knew the terrain too well to have made a wrong turn. He could have had a fainting spell, an attack of dizziness, lost his sense of direction—whatever the reason, he went along in the mistaken belief that he was returning to the station. In reality, he was bound straight for the cliff, lying only a hundred meters or so ahead of him.
Savage, alarmed by his partner’s absence, interrupted his kitchen duty and tried to make radio contact—the transmitter was later found switched on, the frequency setting on ultrashortwave for local transmission. Admittedly, it might have been switched on earlier—if, say, someone in spite of the radio blackout had tried to make contact with the Tsiolkovsky station. But this was deemed highly improbable—first, because the Tsiolkovsky radio had received no calls, distorted or otherwise, and second, because both Savage and Challiers knew better than to attempt any communication just before the dawn, the time when interference was at its peak. Failing to make contact—Challiers by this time was dead—Savage, after suiting up, rushed out into the dark in search of his partner.
In his anxiety over Challiers’s silence, over his sudden and inexplicable disappearance, Savage must momentarily have lost his bearings. Or, as seemed more likely, since he was the more experienced climber of the two, he must have exposed himself unnecessarily to danger while combing the area, taken a fall, and shattered his visor in the process. Sealing the breach with his hand, he struggled back to the station and scrambled up the dome, but before he could seal the outer hatch and lower himself into the pressure chamber, his oxygen supply ran out and he collapsed in a fatal coma on the last rung of the ladder.
Not satisfied with the commission’s version of the dual tragedy, Pirx checked the personality profiles. He paid special attention to Challiers’s, since, according to the commission, he was the inadvertent cause of the two deaths—his own and that of his partner. Challiers, at thirty-five, was an established astrophysicist and an accomplished mountain climber. A man in excellent health, with no known history of any illness, dizzy spells or otherwise. Previously he had done service on the Moon’s Near Side, where he was one of the founding members of the Club of Acrobatic Gymnastics, a typically lunar kind of sport whose adepts were capable of turning double-quadruple flips and of shouldering twenty-five-man pyramids. And this was the same Challiers who suddenly, for no apparent reason, was supposed to have suffered an attack of vertigo a hundred feet away from the station? A man who, even assuming he had been overcome by dizziness, was too weak to take the easiest way back, down the slope, but not too weak to make a detour by way of the cliff, knowing that to reach the salvaged portion of the road he would have to scale the wall of boulders at the rear of the station—and at night, no less?
There was one other detail that to Pirx’s way of thinking (and not only his) directly contradicted the version set forth in the official record. Everything at the station was in its proper place, with one exception: the packets of plates found lying on the kitchen table. Supposing Challiers had really gone up to the shaft, made the switch, but instead of making a detour by way of the cliff, come straight back by the usual route, bringing the exposed plates with him. Now, then, why had he left them on the table? And where was Savage at the time? The commission theorized that the plates in the kitchen were from a previous batch, that one of the scientists must have accidentally left them lying on the table. Yet no plates were ever found on Challiers’s body, a circumstance the commission attributed to his fatal fall—that is, they could have slipped out of the pocket of his space suit and vanished in one of the thousand or more crevices lining the talus.
To Pirx this smacked of stretching the facts to suit the hypothesis.
He shoved the records back into their files, the files into the drawer. He no longer needed them; he already knew them by heart. He told himself—intuited with absolute certitude—that the missing clue was not to be traced to psychology, that the fatalities were caused by something other than a fainting spell, vertigo, or momentary blackout. The answer, he knew, lay somewhere inside or outside the station. With that in mind, he set out to inspect it, compartment by compartment, not in search of clues but simply to familiarize himself with its operational systems. He would do it leisurely; he had time. The pressure chamber seemed like a logical place to begin. First the inner door. Chambers of this type were usually equipped with a mechanism for releasing both the inner and outer hatches, and this one was no exception. The system was designed so that when the outer hatch was open, the inner door could not be opened, this to safeguard against accidents caused by a simultaneous opening of both hatches. As an added precaution, the inner hatch was designed to open toward the inside, so that in an emergency the pressure inside the station would slam it shut with a force of nearly eighteen tons, though the system was far from foolproof: a hand or an object—a tool, for example—could always get caught between the door and the frame, triggering an explosive decompression.
To further complicate matters, the hatch was continuously monitored by a control located in the radio station. An open hatch was registered by a red light on the console, automatically tripping a green monitoring signal. This was a nickel-ringed eye, centered on a tracking screen. A pulsating “butterfly” in the eye meant that the subject outside the station was breathing normally; a calibrated line monitored his position, relative to the output source. The oscilloscope, rotating in unison with the dome-mounted radar antenna, displayed the station’s environment in phosphorescent out-line. Each sweep of the oscilloscope flooded the tube with that familiar fluorescent glow, a space-suited body showing up as a blip of considerable luminosity. By monitoring this elongated emerald-green speck, one could plot its movements against the dimly illuminated background. The upper half of the screen corresponded to the terrain below the northern summit, the bottom half to the southern zone, which included the cliff area, strictly off limits at night.
The remote respiration monitor and the radar tracking system functioned independently of one another. The “eye” was activated by a transmitter connected to the space suit’s oxygen-inlet valve; it operated on a near-infrared frequency, the radar beam on half-centimeter radio waves.
The system was equipped with one tracker and one eye, since station regulations prohibited more than one egress at a time. The one remaining inside the station was required to keep the other under constant surveillance, hastening to the rescue in event of an emergency.
In practice, the plate change was so routine and consumed so little time that the one staying behind could, simply by keeping the door to the radio station open, monitor the instruments without interrupting his kitchen duty. Radio contact could also be maintained, except during the predawn hours when the terminator, that boundary between night and day, whose arrival was always announced by a torrent of static, rendered voice communication next to impossible.
Pirx experimented with the play of signals. He opened the hatch; the red light flashed, the willow-green “eye” went on but remained dormant, its winglike appendages collapsed into listless threads in the absence of any input. The oscilloscope sweep rotated on the face of the tube, conjuring up rigid silhouettes of rock: stone spirits inhabiting a petrified landscape. Not a single light pulse marred its orbital sweep, confirming the lack of input on the breathing monitor.
The next time Langner went out to change the plates, Pirx was able to observe the monitoring system in action.
The red signal flashed, then faded as Langner opened and closed the outer hatch behind him. The butterfly began to palpitate within a few minutes, the pulsations growing more accelerated as the astrophysicist started up the slope at a brisk pace. The light pulse transmitted by his space suit lingered on the screen after each sweep of the tracing beam. Suddenly the butterfly contracted, the screen went blank, the pulse vanished, as Langner descended into the shaft. The lead-lined walls were intercepting the wave transmissions, thought Pirx. Simultaneously the main console flashed a crimson alarm and the profile on the screen changed.
Then Pirx understood why. The radar antenna, its grid constantly gyrating, had reduced the angle of inclination to sweep increasingly distant sectors. The system was responding to the “unknown”: the subject had momentarily slipped out of the range of its electromagnetic vision. Three or four minutes later the butterfly resumed its fluttering motion and the radarscope picked up the missing target. Both components were again registering it, as Langner, now up out of the shaft, began heading back to the station. The alarm signal stayed on; unless switched off manually, it would stay on for another two hours before being shut off automatically. The shutoff was to prevent the system, if inadvertently left on, from consuming too much battery-stored electricity.
The more expert he became at the station’s operational systems, the less complicated he found them to be. Langner never once got in the way of his experiments. To him the commission’s report seemed plausible enough. “Accidents do happen,” he said.
“The plates?” he said in reply to Pirx’s objection. “The plates mean nothing. People do funny things when they’re in a panic. Logic is the first thing to desert them, quicker than life. When that happens, anyone will act irrationally…”
Pirx decided to drop the matter.
The long lunar night was nearing the end of its second week. Pirx, for all his sleuthing, was no wiser now than at the beginning. Maybe he was up against one of those unsolvable, one-in-a-million-type cases… Bit by bit, he began lending Langner a hand with his experiments. He had to pass the time somehow. He even learned how to operate an astrograph (It’s turning out to be a routine training mission after all, he thought) and took turns trekking back and forth to the shaft.