And Wang would remind the old man, very gently, that a paper-forest ranger only made so much money, and that there would have to be more saving before such things could be bought. He did not--_ever_--remind the old man that he, Wang, was stretching a point to keep his grandfather on the payroll as an assistant. Wang Kulichenko patted his horse's rump and urged her softly to step up her pace just a bit. He had a certain amount of territory to cover, and although he wanted to be careful in his checking he also wanted to get home early. Around him, the neatly-planted forest of paper-trees spread knotty, alien branches, trying to catch the rays of the winter-waning sun. Whenever Wang thought of his grandfather's remarks about his ancestors, he always wondered, as a corollary, what those same ancestors would have thought about a forest growing up here, where no forest like this one had ever grown before. They were called paper-trees because the bulk of their pulp was used to make paper--they were of no use whatever as lumber--but they weren't really trees, and the organic chemicals that were leached from them during the pulping process were of far more value than the paper pulp. They were mutations of a smaller plant that had been found in the temperate regions of Mars and purposely changed genetically to grow in the Siberian tundra country, where the conditions were similar to, but superior to, their natural habitat. They looked as though someone had managed to crossbreed the Joshua tree with the cypress and then persuaded the result to grow grass instead of leaves. And the photosynthesis of those grasslike blades depended on an iron-bearing compound that was more closely related to hemoglobin than to chlorophyll, giving them a rusty red color instead of the normal green of Earthly plants. In the distance, Wang heard the whining of the wind increase, and he automatically pulled his coat a little tighter, even though he noticed no increase in the wind velocity around him. Then, as the whine became louder, he realized that it was not the wind. He turned his head toward the sound and looked up. For a long minute he watched the sky as the sound increased in volume, but he could see nothing at first. Then he caught a glimpse of motion, a dot that was hard to distinguish against the cloud-mottled gray sky. What was it? An air transport in trouble? There were two transpolar routes that passed within a few hundred miles of here, but no air transport he had ever seen made a noise like that. Normally they were so high up as to be both invisible and inaudible. Must be trouble of some sort. He reached down to the saddle pack without taking his eyes from the moving speck and took out the radiophone. He held it to his ear and thumbed the call button insistently. _Grandfather!_ he thought with growing irritation as the seconds passed. _Wake up! Come on, old dozer, rouse yourself from your dreams!_