the canal sage to the east. His passage through the plants left a path behind him, a path that slowly closed again as though the canal sage moved deliberately to heal the break. His only hope in that fifteen minutes was to find a giant canal cactus. All Martian plants, the botanists had decided, kept their oxygen supply in their hollow interiors. A full-grown canal cactus was forty feet tall and twenty feet across. If he could break his way into one, it was big enough to supply him with both oxygen and water. But there was no canal cactus in sight, and he could have seen one miles away above this flat expanse of knee-high sage. He moved along stubbornly, the canal sage dragging at his feet. He watched the needle of the oxygen dial sink slowly toward the "empty" mark. The needle hit zero. Shaan stopped. He shook the perspiration from his eyes and looked around him, straining for distance. No friendly cactus reared anywhere above the gray-green sea of sage. No flash of sunlight revealed a distant dome. There was only the frost-rimed expanse of leaves stretching away, the dark cliff rising behind him and the cold, star-studded sky overhead. Shaan felt that he was suffocating. Was the residue of oxygen in his marsuit really depleting that fast, or was it the frantic rebellion of his mind against inevitable death? A great anger swept over him, and with it a bitter defiance. He fumbled at the winged nuts that locked his marshelmet in place. He loosened them, freed them, and dropped them in his pocket. With a wrench, he unsealed the helmet and lifted it from his head. He lifted his naked face to the thin air of Mars. Dizziness swept over him and, with it, nausea. The stars spun in the blue-black sky, and went out for him. He toppled forward, the useless helmet falling from his hands. His unconscious body crashed through the frosty foliage of the canal sage to the turf beneath. Shaan opened his eyes. At once, he was amazed. He had not expected to open them again, ever. It was impossible that he should. He was cold. The cold of death? No. He wouldn't be feeling that. He was in utter blackness, with a fragrant, woodsy