He cut recklessly down the opposite slope and gained the floor of the crater before turning in the direction he had last seen the invader. He cursed himself for having lost sight of him. Momentarily, he slowed his pace, thinking he was ripe for a bushwhacking job. His eyes roved the terrain. No movement, no sign of his quarry. He moved quickly, but warily, attempting to search every inch of the twisted rock formations covering the slope ahead. His eye detected movement off to one side. At the same instant a warning sounded in his brain and he flung himself downward and to the side, hitting the rough ground with a sickening thud. He sensed that the action had saved his life. He crawled between some rock outcroppings, hugging the ground until he reached a vantage point overlooking the area ahead. He waited, trying to search the slope without exposing his position. Minutes passed. He tossed his head restlessly. His eyes roved the plain, searching, attempting to discern movement. No movement--only a world of still life-forms. The plain--its rocks and rills--stretched before him, barren and endless. Strange, he thought, there should be vultures in the sky. And on the plain creosote bushes, purple sage, cactus ... coyotes and rattlesnakes. But ... no! This was an other-world desert, one spawned in the fires of hell--a never-never land of scalding heat and unbelievable cold. He thought it was like a painting by some mad artist. First he had sketched in the plain with infinite care--a white-black, monotonous, unbroken expanse. Afterward he had splashed in the rocks, painting with wild abandon, heedless of design, form or structure, until the plain was a hodgepodge of bizarre formations. They towered, squatted, pierced the sky, crawled along the plain like giant serpents--an orgy in rock without rhyme or reason. Somewhere in the lithic jungle his quarry waited. He would flush him out. He thought that the sniper must be getting low on oxygen. He couldn't afford to waste time. He had to reach Red Dog soon--if he were to live. Crag checked his oxygen meter and began moving forward, conscious that the chase would be governed by his oxygen supply. He'd have to remember that. He reached a clearing on the slope just as the sniper disappeared into the rock shadows on the opposite side. He hesitated. Would the pursued man be waiting ... covering the trail behind him? He decided not to chance crossing it and began skirting around its edge, fretting at the minutes wasted. His earphones crackled and Prochaska's voice came, a warning through the vacuum: "Nagel says your oxygen must be low." He glanced at the indicator on his cylinder. Still safe. He studied the rocks ahead and told Prochaska: "I've got to keep this baby from reaching Red Dog." "Watch yourself. Don't go beyond the point of no return." Prochaska's voice held concern. "Stop worrying."