Produced by Greg Weeks, Mary Meehan and the Online Distributed Proofreading Team at http://www.pgdp.net CATALYSIS BY POUL ANDERSON _Man is a kind of turtle. Wherever he goes, he will always carry a shell holding warmth and air--and with them his human failings...._ [Transcriber's Note: This etext was produced from Worlds of If Science Fiction, February 1956. Extensive research did not uncover any evidence that the U.S. copyright on this publication was renewed.] When you looked outside, it was into darkness. Going out yourself, you could let your eyes accommodate. At high noon, the sun was a sharp spark in a dusky heaven, and its light amounted to about one-ninth of one percent of what Earth gets. The great fields of ice and frozen gases reflected enough to help vision, but upthrust crags and cliffs of naked rock were like blackened teeth. Seventy hours later, when Triton was on the other side of the primary that it always faced, there was a midnight thick enough to choke you. The stars flashed and glittered, a steely twinkle through a gaunt atmosphere mostly hydrogen--strange, to see the old lost constellations of Earth, here on the edge of the deep. Neptune was at the full, a giant sprawling across eight degrees of sky, bluish gray and smoky banded, but it caught so little sunlight that men groped in blindness. They set up floodlights, or had lamps glaring from their tracs, to work at all. But nearly everything went on indoors. Tunnels connected the various buildings on the Hill, instruments were of necessity designed to operate in the open without needing human care, men rarely had occasion to go out any more. Which was just as well, for it takes considerable power and insulation to keep a man alive when the temperature hovers around 60 degrees Kelvin. And so you stood at a meter-thick port of insulglas, and looked out, and saw only night. Thomas Gilchrist turned away from the view with a shudder. He had always hated cold, and it was as if the bitterness beyond the lab-dome had seeped in to touch him. The cluttered gleam of instruments in the room, desk piled high with papers and microspools, the subdued chatter of a computer chewing a problem, were comforting.