dislodged by a boot, cascading down with a rippling echo. The intermittent squeak of a shoulder strap or a metal fitting lent their expedition a certain
It was a planet with sharply defined seasons. Hardly had they landed at the tail end of summer when an alpine autumn, lush with reds and golds, began fading in the valleys. Yet even though leaves were borne on the foam of rushing streams, the sun was still warm—on cloudless days, even sweltering—on the tableland. Only the thickening fog signaled the approach of snow and frost. But by then the planet would be deserted, and to Pirx the prospect of that consummate wasteland cast in white suddenly seemed desirable beyond all else.
The brightening, so gradual as to be imperceptible, with every step brought a new detail of the landscape into prominence. The sky had taken on that pallor between night and day—dawnless, stark, hushed, as if hermetically sealed in a sphere of cooling glass. A little farther up, they passed through a fog bank, its wispy strands clinging to the ground, and after they emerged Pirx saw their destination, still untouched by sunlight but now at least whitened by the dawn: a rock-ribbed buttress that reached up to the main ridge, up to where, a few hundred meters higher, its twin peak, the most prominent, loomed blackly. At one point the rib flared out into a troughlike basin; in this saddle Aniel had conducted his last survey.
It was a straightforward ascent and descent—no surprises, no crevasses, nothing but gray scree dappled with chick-yellow mildew. As he trod nimbly from one clattering rock pile to another, Pirx fixed on the black wall leaning against the sky and, perhaps to distract himself, imagined he was making an ordinary ascent Earthside. Suddenly these crags seemed quite natural to him, the illusion of a conquest in the making rendered even more compelling by their vertical climb toward the notched spine heaving up out of the scree. The buttress ran one-third of the way up the face before disintegrating in a riot of wedged slabs, whence a sheer rock face shot straight up like a flight arrested. A hundred meters higher, the face was cleaved by a vein of diabase—red-tinted, brighter than granite—that bulged above the surface and snaked across the flank, like a trail of varying width.
Pirx’s eyes were held in thrall by the summit’s sublime outline, though as they climbed higher, and, as was usual with a mountain viewed from below, it receded farther, and the abrupt foreshortenings broke it up into a series of overlapping planes, the base lost its former flatness, and columns sprang up—a wealth of faults, shelves, aimlessly winding chimneys, a chaos of old fissures, an anarchy of cluttered accretion, momentarily illumined by the top now gilded by the sun’s first rays, fixed and strangely placid, then once more swallowed by shadow. Pirx could not tear his eyes from it, from this colossus that even on Earth would have commanded respect, challenging the climber with that rudely jutting vein of diabase. The stretch from there to the gold-plated summit looked short and easy compared with the overhangs, especially the largest of them, whose lower edge glistened with ice or moisture, reddish-black, like congealed blood.
Pirx let his imagination run wild, conjuring up not the cliff of some anonymous highland under a foreign sun, but a mountain surrounded by a lore of assaults and reverses, somehow distinct, unique, like a familiar face whose every wrinkle and scar contained a history of its own. Its sinewy, snakelike cracks on the border of visibility, its dark, threadlike ledges, its shallow grooves might have constituted the highest point achieved in a series of attempts, the sites of prolonged bivouacs, of silent reckonings, of momentous assaults and humiliating defeats, disasters sustained even though every variety of tactical and technical gimmick was applied. A mountain so bound up with the fate of man that every climber vanquished by it came back again and again, always with the same store of faith and hope in victory, bringing to each successive pass a new fixed route with which to storm the petrified relief. It could have been a wall with a history of detours, flanking movements, each with its own chronicle of successes and victims, documented by photos bearing the dotted lines of trails, little
Massena walked ahead of him, slightly stooped, in a light whose growing limpidity annulled all illusion of an easy ascent, this illusion of easy access and safe passage having been fostered by the bluish haze that had peacefully engulfed every fragment of the glimmering cliff. The day, raw and full, had caught up with them; their shadows, exaggeratedly large, rolled and pitched under the ridge of the alluvial cone. The talus was fed by two couloirs, brimming with night, and the detritus ran straight up before being consumed by unrelieved black.
The massif could no longer be encompassed by the eye. Proportions had shifted, and the wall, similar to any other from a distance, now revealed its unique topography, its singular configuration. Bellying outward was a mighty buttress that rose out of a tangle of slab and plate, shot up, swelled, and spread until it obscured everything else, to stand alone, encircled by the dank gloom of places never touched by light. They had just stepped onto a patch of permanent snow, its surface strewn with the remnants of flying debris, when Massena began to slacken his pace, then finally stopped, as if distracted by some noise. Pirx, who was the first to catch up with him, saw him make a tapping gesture on his ear, the one fitted with the olive-sized microphone, and immediately grasped its meaning.
“Any sign of him?”
Massena nodded and brought the metal-detector rod up close to the dirty, snow-crusted surface. The soles of Aniel’s boots were impregnated with a radioactive isotope; the Geiger counter had picked up his trail. Though the trail was still alive from the day before, there was no way to read any direction in it—whether deposited on the robot’s way up, or back. But at least they knew they were on the right track. From here on in, they took their time.
The dark buttress should have loomed just ahead, but Pirx knew how easy it was to misjudge distances in the mountains. They climbed higher, above the snowline and rubble, proceeding along an older, smaller ridge notched with rounded pinnacles, and in the dead silence Pirx thought—wishful thinking?—he could hear Massena’s earphones crackling. Intermittently, Massena would stop, fan the air with the end of the aluminum rod, lower it until it nearly touched the rock, trace loops and figure eights like a magician, then, relocating the trail, move on. As they neared Aniel’s surveying site, Pirx scoured the area for any signs of the missing robot.
The face was deserted. The easiest part of the route was now behind them; before them towered a series of slabs that cropped up from the foot of the buttress at diverse inclinations. The whole resembled a gigantic cross- section of the wall’s strata, the partly exposed interior revealing the core’s oldest formation, fissured in places under the sheer rock mass lifting several kilometers up into the sky. Another forty or a hundred paces and—an impasse.
Massena worked in a circle, waving the end of the detector rod, squinting—his sunglasses were already propped up on his forehead—rotating aimlessly, expressionless, before stopping in his tracks a dozen or so meters away.
“He was here quite a while.”
“How can you tell?”
Massena shrugged, plucked the olive from his ear, and handed Pirx the earphone dangling on its thin connecting wire. Then Pirx heard it for himself, a twittering and screeching that at times rose to a whining plaint. The rock face was devoid of any prints or traces—nothing but that unremitting sound filling the skull with its strident crackling, the intensity of which was such that nearly every millimeter of rock testified to the robot’s prolonged and diligent presence. Gradually Pirx came to discern a certain logic in the apparent chaos: Aniel had apparently come up by the same route they had taken, set up the tripod, got the camera into position, and circled it several times in the process of surveying and photographing, even shifting it in search of the most favorable observation points. Right, that made sense. But then what?
Pirx began moving out concentrically, spiral-fashion, in hope of picking up his centripetal trail, but none of the trails led back to the starting point. Much as if Aniel had retraced his every step, which did not seem likely: not being equipped with a gamma-ray counter, he could hardly have reconstructed his return route to within a few centimeters. Krull made some comment to Massena which the circling Pirx ignored, for his attention was diverted by a sound, brief but distinct, transmitted by his earphones. He began backtracking, almost millimeter by millimeter. Here—I’m sure it was here. Staring intently, he scanned the terrain, squinting the better to concentrate on the whining. The rediscovered trail lay at the base of the cliff, as if, instead of taking the trail campward, the robot had headed straight for the vertical buttress.
