"Take two swallows, no more," he said, holding the canteen to her mouth. "Just summer change, that's all. Happens to us every year on Anvhar--only not that violently, of course. In the winter our bodies store a layer of fat under the skin for insulation and sweating almost ceases completely. Lot of internal changes, too. When the weather warms up the process is reversed. The fat is metabolized and the sweat glands enlarge and begin working overtime as the body prepares for two months of hard work, heat and little sleep. I guess the heat here triggered off the summer change early." "You mean--you've adapted to this terrible planet?" "Just about. Though it does feel a little warm. I'll need a lot more water soon, so we can't remain here. Do you think you can stand the sun if I carry you?" "No, but I won't feel any better staying here." She was light-headed, scarcely aware of what she said. "Keep going, I guess. Keep going." As soon as she was out of the shadow of the rock the sunlight burst over her again in a wave of hot pain. She was unconscious at once. Her slight weight was no burden to Brion and he made his best speed, heading toward the spot on the horizon where the sun would set. Without water he knew he could not last more than a day or two at best. When sunset came he was still walking steadily. Only when the air chilled did he stop to dress them both in the warm clothes and push on. Lea regained consciousness in the cool night air and finished the last mouthfuls of water. She wanted to walk, but could only moan with pain when her burned feet touched the ground. He put ointment on them and wrapped them in cloth. They were too swollen to go back into the ragged shoes. Lifting his burden he walked on into the night, following the guiding stars. * * * * * Except for the nagging thirst, it was an easy night. He wouldn't need sleep for two or three days more, so that didn't bother him. His muscles had a plentiful supply of fuel at hand in the no longer wanted subcutaneous fatty layer. Metabolizing it kept him warm. By running at a ground-eating pace whenever the footing was smooth he made good time. By dawn he was feeling a little tired and was at least ten kilos lighter due to the loss of the burned up fat. There was no sight of the city yet. This was the last day. Massive as the adaptation of his body was to the climate, it still needed water to function. As his pores opened in the heat he knew the end was very close. Weaving, stumbling, trying not to fall with the unconscious girl, he climbed dune after unending dune. Before his tortured eyes the sun expanded and throbbed like a gigantic beating heart. He struggled to the top of the mountain of sand and looked at the Disan standing a few feet away.