The Human Edge

by Gordon R. Dickson

  He was slow, very slow, about it. After agonizing minutes Cal saw Maury's hand come around the edge of the boss. Slowly he passed the projecting rock to the rock slab. His face was pale and rigid when he got to where Cal stood. His breath came in short, quick pants.

  Cal signaled on the rope again. In considerably less time than Maury had taken Doug came around the boss. There was a curious look on his face.

  "What is it?" asked Cal.

  Doug glanced back the way he had come. "Nothing, I guess," he said. "I just thought I saw something moving back there. Just before I went around the corner. Something I couldn't make out."

  Cal stepped to the edge of the rock slab and looked as far back around the boss as he could. But the ledge they had come from was out of sight. He stepped back to the ledge.

  "Well," he said to the others, "the next stretch is easier."

  VI

  It was. The crack up which they climbed now slanted to the right at an almost comfortable angle.

  They went up it using hands and feet like climbing a ladder. But if it was easy, it was also long, covering better than a hundred feet of vertical rock face. At the top, where the crack pinched out, there was the second tricky traverse across the rock face, of some eight feet. Then a short climb up a cleft and they stood together on top of the ridge.

  Down below, they had been hidden by the mountain walls from the high winds above. Now for the first time, as they emerged onto the ridge they faced and felt them.

  The warmsuits cut out the chill of the atmosphere whistling down on them from the mountain peak, but they could feel the pressure of it molding the suits to their bodies. They stood now once more in sunlight. Behind them they could see the hanging valley and the Harrier. Ahead was a cwm, a hollow in the steep mountainside that they would have to cross to get to a further ridge leading up to the mountain peak. Beyond and below the further ridge, they could see the far, sloping side of the mountain and, black against it, the tiny, oil-drum-end fragment of alien ship with a dot of white just outside it.

  "We'll stay roped," said Cal. He pointed across the steep-sloping hollow they would need to cross to reach the further rocky ridge. The hollow seemed merely a tilted area with occasional large rock chunks perched on it at angles that to Earth eyes seemed to defy gravity. But there was a high shine where the sun's rays struck.

  "Is that ice?" said Maury, shading his eyes.

  "Patches of it. A thin coating over the rocks," said Cal. "It's time to put on the crampons."

  They sat down and attached the metal frameworks to their boots that provided them with spiked footing. They drank sparingly of the water they carried and ate some of their rations. Cal glanced at the descending sun, and the blue-black sky above them. They would have several hours yet to cross the cwm, in daylight. He gave the order to go, and led off.

  He moved carefully out across the hollow, cutting or kicking footholds in patches of ice he could not avoid. The slope was like a steep roof. As they approached the deeper center of the cwm, the wind from above seemed to be funnelled at them so that it was like a hand threatening to push them into a fall.

  Some of the rock chunks they passed were as large as small houses. It was possible to shelter from the wind in their lees. At the same time, they often hid the other two from Cal's sight, and this bothered him. He would have preferred to be able to watch them in their crossings of the ice patches, so that if one of them started to slide he would be prepared to belay the rope. As it was, in the constant moan and howl of the wind, his first warning would be the sudden strain on the rope itself. And if one of them fell and pulled the other off the mountainside, their double weight could drag Cal loose.

  Not for the first time, Cal wished that the respirator masks they wore had been equipped with radio intercom. But these were not and there had been no equipment aboard the Harrier to convert them.

  * * *

  They were a little more than halfway across when Cal felt a tugging on the line.

  He looked back. Maury was waving him up into a shelter of one of the big rocks. He waved back and turned off from the direct path, crawling up into the ice-free overhang. Behind him, as he turned, he saw Maury coming toward him, and behind Maury, Doug.

  "Doug wants to tell you something!" Maury shouted against the wind noise, putting his mask up close to Cal's.

  "What is it?" Cal shouted.

  "—Saw it again!" came Doug's answer.

  "Something moving?" Doug nodded. "Behind us?" Doug's mask rose and fell again in agreement "Was it one of the aliens?"

  "I think so!" shouted Doug. "It could be some sort of animal. It was moving awfully fast—I just got a glimpse of it!"

  "Was it—" Doug shoved his masked face closer, and Cal raised his voice—"was it wearing any kind of clothing that you could see?"

  "No!" Doug's head shook back and forth.

  "What kind of life could climb around up here without freezing to death—unless it had some protection?" shouted Maury to them both.

  "We don't know!" Cal answered. "Let's not take chances. If it is an alien, he's got all the natural advantages. Don't take chances. You've got your gun, Doug. Shoot anything you see moving!"

  Doug grinned and looked harshly at Cal from inside his mask.

  "Don't worry about me!" he shouted back. "Maury's the one without a gun."

  "We'll both keep an eye on Maury! Let's get going now. There's only about another hour or so before the sun goes behind those other mountains—and we want to be in camp underneath the far ridge before dark!"

  He led off again and the other two followed.

  As they approached the far ridge, the wind seemed to lessen somewhat. This was what Cal had been hoping for—that the far ridge would give them some protection from the assault of the atmosphere they had been enduring in the open. The dark wall of the ridge, some twenty or thirty feet in sudden height at the edge of the cwm, was now only a hundred yards or so away. It was already in shadow from the descending sun, as were the downslope sides of the big rock chunks. Long shadows stretched toward a far precipice edge where the cwm ended, several thousand feet below. But the open icy spaces were now ruddy and brilliant with the late sunlight. Cal thought wearily of the pup tents and his sleeping bag.

  * * *

  Without warning a frantic tugging on the rope roused him. He jerked around, and saw Maury, less than fifteen feet behind him, gesturing back the way they had come. Behind Maury, the rope to Doug led out of sight around the base of one of the rock chunks.

  Then suddenly Doug slid into view.

  Automatically Cal's leg muscles spasmed tight, to take the sudden jerk of the rope when Doug's falling body should draw it taut. But the jerk never came.

  Sliding, falling, gaining speed as he descended the rooftop-steep slope of the cwm, Doug's body no longer had the rope attached to it. The rope still lay limp on the ground behind Maury. And then Cal saw something he had not seen before. The dark shape of Doug was not falling like a man who finds himself sliding down two thousand feet to eternity. It was making no attempt to stop its slide at all. It fell limply, loosely, like a dead man—and indeed, just at that moment, it slid far upon a small, round boulder in his path which tossed it into the air like a stuffed dummy, arms and legs asprawl, and it came down indifferently upon the slope beyond and continued, gaining speed as it went.

  Cal and Maury stood watching. There was nothing else they could do. They saw the dark shape speeding on and on, until finally it was lost for good among the darker shapes of the boulders farther on down the cwm. They were left without knowing whether it came eventually to rest against some rock, or continued on at last to fall from the distant edge of the precipice to the green, unknown depth that was far below them.

  After a little while Maury stopped looking. He turned and climbed on until he had caught up with Cal. His eyes were accusing as he pulled in the loose rope to which Doug had been attached. They looked at it together.

  The rope's end had been cut as
cleanly as any knife could have cut it.

  The sun was just touching the further mountains. They turned without speaking and climbed on to the foot of the ridge wall.

  Here the rocks were free of ice. They set up a single pup tent and crawled into it with their sleeping bags together, as the sun went down and darkness flooded their barren and howling perch on the mountainside.

  VII

  They took turns sitting up in their sleeping bags, in the darkness of their tiny tent, with Cal's gun ready in hand.

  Lying there in the darkness, staring at the invisible tent roof nine inches above his nose, Cal recognized that in theory the aliens could simply be better than humans—and that was that. But, Cal, being the unique sort of man he was, found that he could not believe such theory.

  And so, being the unique sort of man he was, he discarded it. He made a mental note to go on trying to puzzle out the alien's vulnerability tomorrow . . . and closing his eyes, fell into a light doze that was the best to be managed in the way of sleep.

  When dawn began to lighten the walls of their tent they managed, with soup powder, a little of their precious water and a chemical thermal unit, to make some hot soup and get it into them. It was amazing what a difference this made, after the long, watchful and practically sleepless night. They put some of their concentrated dry rations into their stomachs on top of the soup and Cal unpacked and set up the small portable still.

  He took the gun and his ice-hammer and crawled outside the tent. In the dawnlight and the tearing wind he sought ice which they could melt and then distill to replenish their containers of drinking water. But the only ice to be seen within any reasonable distance of their tent was the thin ice-glaze—verglas, mountaineers back on Earth called it—over which they had struggled in crossing the cwm the day before. And Cal dared not take their only gun too far from Maury, in case the alien made a sudden attack on the tent.

  There was more than comradeship involved. Alone, Cal knew, there would indeed be no hope of his getting the Messenger to the mountaintop. Not even the alien could do that job alone—and so the alien's strategy must be to frustrate the human party's attempt to send a message.

  It could not be doubted that the alien realized what their reason was for trying to climb the mountain. A race whose spaceships made use of the principle of no-time in their drives, who was equipped for war, and who responded to attack with the similarities shown so far, would not have a hard time figuring out why the human party was carrying the equipment on Cal's pack up the side of a mountain.

  More, the alien, had he had a companion, would probably have been trying to get message equipment of his own up into favorable dispatching position. Lacking a companion his plan must be to frustrate the human effort. That put the humans at an additional disadvantage. They were the defenders, and could only wait for the attacker to choose the time and place of his attempt against them.

  And it would not have to be too successful an attempt, at that. It would not be necessary to kill either Cal or Maury, now that Doug was gone. To cripple one of them enough so that he could not climb and help his companion climb, would be enough. In fact, if one of them were crippled Cal doubted even that they could make it back to the Harrier. The alien then could pick them off at leisure.

  * * *

  Engrossed in his thoughts, half-deafened by the ceaseless wind, Cal woke suddenly to the vibration of something thundering down on him.

  He jerked his head to stare upslope—and scrambled for his life. It was like a dream, with everything in slow motion—and one large chunk of rock with its small host of lesser rocks roaring down upon him.

  Then—somehow—he was clear. The miniature avalanche went crashing by him, growing to a steady roar as it grew in size sweeping down alongside the ridge. Cal found himself at the tent, from which Maury was half-emerged, on hands and knees, staring down at the avalanche.

  Cal swore at himself. It was something he had been told, and had forgotten. Such places as they had camped in last night were natural funnels for avalanches of loose rock. So, he remembered now, were wide cracks like the sloping one in the cliff face they had climbed up yesterday—as, indeed, the cwm itself was on a large scale. And they had crossed the cwm in late afternoon, when the heat of the day would have been most likely to loosen the frost that held precariously balanced rocks in place.

  Only fool luck had gotten them this far!

  "Load up!" he shouted to Maury. "We've got to get out of here."

  Maury had already seen that for himself. They left the pup-tent standing. The tent in Cal's load would do. With that, the Messenger, their climbing equipment, their sleeping bags and their food and water, they began to climb the steeply sloping wall of the ridge below which they had camped. Before they were halfway up it, another large rock with its attendant avalanche of lesser rocks came by below them.

  Whether the avalanches were alien-started, or the result of natural causes, made no difference now. They had learned their lesson the hard way. From now on, Cal vowed silently, they would stick to the bare and open ridges unless there was absolutely no alternative to entering avalanche territory. And only after every precaution.

  In the beginning Cal had kept a fairly regular check on how Maury was doing behind him. But as the sun rose in the bluish-black of the high altitude sky overhead the weariness of his body seemed to creep into his mind and dull it. He still turned his head at regular intervals to see how Maury was doing. But sometimes he found himself sitting and staring at his companion without any real comprehension of why he should be watching over him.

  The blazing furnace of K94 overhead, climbing toward its noontime zenith, contributed to this dullness of the mind. So did the ceaseless roaring of the wind which had long since deafened them beyond any attempt at speech. As the star overhead got higher in the sky this and the wind noise combined to produce something close to hallucinations . . . so that once he looked back and for a moment seemed to see the alien following them, not astraddle the ridge and hunching themselves forward as they were, but walking along the knife-edge of rock like a monkey along a branch, foot over foot, and grasping the rock with toes like fingers, oblivious of the wind and the sun.

  * * *

  Cal blinked and, the illusion—if that was what it was—was gone. But its image lingered in his brain with the glare of the sun and the roar of the wind.

  His eyes had fallen into the habit of focusing on the rock only a dozen feet ahead of him. At last he lifted them and saw the ridge broaden, a black shadow lying sharply across it. They had come to the rock walls below the hanging glacier they had named the Hook.

  They stopped to rest in the relative wind-break shelter of the first wall, then went on.

  Considering the easiness of the climb they made remarkably slow progress. Cal slowly puzzled over this until, like the slow brightening of a candle, the idea grew in him to check the absolute altimeter at his belt

  They were now nearly seven thousand feet higher up than they had been at the wreck of the Harrier. The mask respirators had been set to extract oxygen for them from the local atmosphere in accordance with the Harrier altitude. Pausing on a ledge, Cal adjusted his mask controls.

  For a minute there seemed to be no difference at all. And then he began to come awake. His head cleared. He became sharply conscious, suddenly of where he stood—on a ledge of rock, surrounded by rock walls with, high overhead, the blue-black sky and brilliant sunlight on the higher walls. They were nearly at the foot of the third, and upper, battlement of the rock walls.

  He looked over the edge at Maury, intending to signal the man to adjust his mask controls. Maury was not even looking up, a squat, lumpish figure in the warmsuit totally covered, with the black snout of the mask over his face. Cal tugged at the rope and the figure raised its face. Cal with his gloved hands made adjusting motions at the side of his mask. But the other's face below, hidden in the shadow of the faceplate, stared up without apparent comprehension. Cal started to yell down to him
—here the wind noise was lessened to the point where a voice might have carried—and then thought better of it.

  Instead he tugged on the rope in the signal they had repeated an endless number of times; and the figure below, foreshortened to smallness stood dully for a moment and then began to climb. His eyes sharpened by the fresh increase in the oxygen flow provided by his mask Cal watched that slow climb almost with amazement carefully taking in the rope and belaying it as the other approached.

  There was a heaviness, an awkwardness, about the warmsuited limbs, as slowly—but strongly enough—they pulled the climber up toward Cal. There was something abnormal about their movement. As the other drew closer, Cal stared more and more closely until at last the gloves of the climber fastened over the edge of the ledge.

  Cal bent to help him. But, head down not looking, the other hoisted himself up alongside Cal and a little turned away.

  Then in that last instant the combined flood of instinct and a lifetime of knowledge cried certainty. And Cal knew.

  The warmsuited figure beside him was Maury no longer.

  VIII

  Reflexes have been the saving of many a man's life. In this case, Cal had been all set to turn and climb again, the moment Maury stood beside him on the edge. Now recognizing that somewhere among these rocks, in the past fumbling hours of oxygen starvation, Maury had ceased to live and his place had been taken by the pursuing alien, Cal's reflexes took over.

  If the alien had attacked the moment he stood upright on the ledge, different reflexes would have locked Cal in physical combat with the enemy. When the alien did not attack, Cal turned instinctively to the second prepared response of his body and began automatically to climb to the next ledge.

  There was no doubt that any other action by Cal, any hesitation, any curiosity about his companion would have forced the alien into an immediate attack. For then there would have been no reason not to attack. As he climbed, Cal felt his human brain beginning to work again after the hours of dullness. He had time to think.