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 aroma in his nostrils. He was lying flat on his stomach, on a surface that was not soft, but springy. Had he been rescued? Was he in a hospital somewhere? In a dome? He moved his fingers. They clutched chill, moldy sod. But he was breathing. The air was sweet and keen, like the air of a terrestrial mountain top. He was alive. He pulled his knees under him slowly and sat up. His bare head struck a flimsy, rustling barrier and thrust through. The air rushed from his lungs and he gasped in the thin, icy-cold Martian air. He had a single glimpse of jewelled stars in a velvet sky before he threw himself prone beneath the foliage again. He lay there, recovering his breath. Slowly, realization came to him. He was under the canopy formed by the foliage of myriads of canal sage plants. The leaves formed a tightly packed roof 18 inches above the ground. Perhaps the plants did store oxygen in their hollow stems. But they trapped it beneath the solid cover of their foliage, too, forming a thin layer of breathable atmosphere along the surface of the canal. Shaan laughed, a harsh, dry laugh. For years people had been crunching around through the canal sage, harvesting it sometimes for fuel and other purposes. All that time they had not realized they were wading through a layer of breathable oxygen at their very ankles. The foliage trapped the daytime heat, too. That was why Shaan was only cold, instead of nearly frozen. Carefully, he got to hands and knees and began to crawl. At once, he ran into a tangle of plant stems. He could make no headway. He subsided and lay down again, thinking it over. He was hungry and thirsty. Canal sage was better cooked, but it was edible raw. All he had to do was reach out his hands and cram the thick leaves in his mouth, being careful not to denude too much of the canopy above him. After a while, he was well fed. The leaves had partially assuaged his thirst, too.