Donald Moffitt - Genesis 01

stretched for three hundred miles. Below, the tangled root system formed what at this distance looked like an equally flat and solid floor. Its modified structure drank in and conserved every molecule of moisture that escaped from the miserly canopy above and sent signals to the living light sail to keep it on course in its search for water ice. It dwarfed all but the largest comets. When it caught a comet in its fibrous net, it shed its adventitious leaves within the circle of contact and sent out root hairs to melt and drink every last drop. And the tree celebrated another minute fraction of growth.
    “It’s a world! ” Kerthin exclaimed in awe. “But it’s alive! ” Her hand clutched Bram’s.
    Trist’s head bobbed in her direction. “Think of them, spreading slowly outward between the stars,” he said cheerfully. “Acquiring their own ecology. Parasites like us, for example. They could make planets obsolete.”
    Kerthin did not rise to the bait. Bram knew that Trist had overheard her remark about migration and was teasing her.
    “You may have something there,” Bram said, keeping his voice serious.
    “Sure, back to the treetops after forty million years,” Trist said.
    The boat’s attitude jets coughed diffidently, and the cabin made a quarter rotation. Bram’s orientation changed. He was no longer looking down at a floor of roots, up at an umbrella of leaves. They were now the walls of an impossible chasm, and he was looking up through the top of the viewdome at it.
    This time his senses agreed with his intellect. What he viewed as “up” was “up” for the tree, too. One hundred and fifty miles over his head was the axle that spun the twin disks.
    Others had the same thought. “There’s the trunk,” Trist was telling Nen. “Can you see it?”
    Bram peered straight up at the slice of night visible between the two living walls. The trunk could be seen as a mottled gray bridge that joined them. It was as straight as centrifugal force had grown it, except at either end, where it fanned out gracefully to give rise to the circles of reaching growth.
    The thrusters gave the hovering craft a measured kick and sent it rising up the living canyon.
    “It’s a yo-yo,” Trist said suddenly.
    “Huh?”
    “The tree is shaped exactly like a yo-yo. Didn’t you ever have one when you were a child? And now I bet I know how we’re going to get transferred to the rim.”
    It took another hour to reach the trunk. For the last twenty miles, the pilot sent the craft rolling and timed each small burst of the braking jets for the moments when he was pointed toward his destination. He finished up nicely with his trimming nozzles aimed for the vertical— compressed gas jets that wouldn’t hurt the tree.
    The tumbling had disoriented some passengers and produced nausea. Somebody across the way was being sick in one of the pinchbasins that had been provided for that purpose. “First casualty,” Trist said.
    Bram looked at Kerthin. Her face had gone the color of putty, but she swallowed hard. “So much for the consideration of your five-legged friends,” she said.
    “Be fair, Kerth,” he said. “This is the way they always do it. The Nar don’t get motion sickness with their kind of nervous system. They can’t change their touchdown routines just because they’ve got a load of human passengers.”
    “Or maybe they could, if it had occurred to them,” she said angrily.
    The tree trunk hovered overhead, a solid wall of patchy gray bark. Bram could see Nar in space suits clinging to it, moving like disembodied claws along the surface. They didn’t seem to be at all inconvenienced by the fact that they were hanging upside down off a spinning cylinder that could hurl them off into space. This close to the center of rotation of the tree, centrifugal force was so small as to be almost negligible. If one of them lost his grip and started drifting outward, he would have ample time to make a grab for it.
    And the Nar were better suited for space work than humans, anyway. Even leaving the prehensile legs aside, they could hold on with two arms and still have three to work with at any given moment.
    Two of the space-suited figures deliberately broke contact with the rough expanse of the trunk. Several passengers gave a gasp as they saw them drifting downward like five-pointed snowflakes.
    But not quite. One of them was trailing a gossamer cable attached to a great curved hook cradled between two of his