Lying down, Leeda adjusted her head-bubble so that it became opaque; conserving the warmth that leaked off so rapidly from a transparent object. At long intervals she tried to move away from Rick who had settled right beside her. But each time his hand grabbed her firmly, forcing her back to the sand. He apparently intended to stay awake all night so she wouldn't sneak off. * * * * * When the morning of the fourth day arrived, they rose and once more moved stiffly, without a word for one another, across the wastes on the route that Leeda had selected. Without quite knowing how it had happened, Leeda twice found herself on her knees on the sand. She knew she had been staggering; that her strength had long past left her; yet she was still amazed that her legs would not do the bidding of her mind. Each time she fell, Rick jerked her roughly to her feet and supported her until her legs moved automatically again. His eyes were red-rimmed; his lips a ghastly slash of scabs and sores. About mid-morning he began to mumble incoherently, as though his voice alone could keep him sane. The only recognizable word that slid through his lips was, "Water! Water!" It beat like the tone of a bass Callisto Satan Temple drum on Leeda's strained mind until she began to vision waterfalls and huge cakes of ice on the desert before her. Reality and imagination became mixed until she wondered if there was a place called Mars and if the past few days were real. And it became noon; then mid-afternoon. Suddenly the water-hole appeared as a dark spot on the featureless landscape before them. Distinguishable only by the lichens that surrounded it. They both broke into a shuffling, jerky trot. Leeda was yards behind Rick when he reached the mud-hole. Instead of flinging himself down to the moisture, he stiffened, then his voice broke into a babbling cackle. He pointed to the perma-metal sign staked in the watery mud. A Death's Head stood embossed on its surface; the Interplanetary symbols for DEATH etched into the age-resisting metal. Then his hand moved like doom to the skeleton that lay, head touching the red mud, on the edge of the hole. Ignoring Leeda completely, his voice broke into a hideous sing-song of wild laughter; and the word, "Poison," tumbled endlessly from his throat. He stopped abruptly and turned to the desert. The lines of agony on his face smoothed out and the old sardonic grin twisted its way to his cheeks. Only his eyes gleamed madly. With a tremendous effort, he said loudly, "Water! There. Only a little way off." And he staggered off into the desert, his arms extended eagerly, his hands fluttering aimlessly. Leeda watched him go. Watched him chase his mirage out into the Martian wastes that extended for hundreds of miles without the slightest trace of water. Watched him stagger into oblivion until he became small with the distance.