What good would it have done him, anyhow? There would be no rescue for him. The radio equipment had been removed from his marshelmet. Even if it hadn't, no one would help a branded man. * * * * * He saw the green expanse of the canal when he was still far away from it. It was a thin line that broadened as he approached, panting, getting the best he could from his weary legs with long, floating leaps. He reached the edge of the cliff. The canal was a hundred feet below him, too far to jump, even on Mars. He walked a mile southward along the rim, seeking a downward ledge. There was no ledge. But Shaan found a roughness of projecting rocks, where the cliff was not entirely perpendicular. He scrambled down. He jumped down the last twenty feet. He landed with a muffled crunch of broken branches in the canal sage that stretched in unbroken gray-green expanse from the base of the cliff, as far as the eye could see. He got to his feet. The canal sage was uniformly knee-high. It was so close-packed that the tops formed an apparently solid carpet on the canal bottom. He checked his oxygen dial. Only fifteen minutes' supply left. Even if he were on course, the private dome was at least twenty miles away. He was in the shadow of the cliff here. The small sun of Mars was low in the west. Above him, the brightest stars already shone in the dark blue sky. The cold of night was beginning to descend. There was frost on the leaves of the canal sage. He switched his marsuit temperature control from "cool" to "heat," but left it low. His body temperature would keep him warm enough as long as he was moving. Fifteen minutes and then death. Shaan shrugged. He started walking, straight away from the cliff toward the distant sunlight that still touched 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.