"Why not? If it grows, it metabolizes. If it metabolizes, we can kill it. Axiom number seventeen, paragraph number four." "Oh, it metabolizes, all right, but you'd better find yourself another axiom, pretty quick." "Why?" "Because it not only metabolizes, it _consumes_. There's no sign of the usual protein-carbohydrate-fat metabolism going on here. This baby has an enzyme system that's straight from hell. It bypasses the usual metabolic activities that produce heat and energy and gets right down to basic-basic." Jenkins swallowed. "What do you mean?" "It attacks the nuclear structure of whatever matter the creature comes in contact with. There's a partial mass-energy conversion in its rawest form. The creature goes after carbon-bearing substances first, since the C seems to break down more easily than anything else--hence its preference for plant and animal material over non-C stuff. But it can use anything if it has to--" Jenkins stared at the little biochemist, an image in his mind of the pink creature in the hold, growing larger by the minute as it ate its way through the hydroponics, through the dry stores, through-- "Is there anything it _can't_ use?" "If there is, I haven't found it," Hrunta said sadly. "In fact, I can't see any reason why it couldn't consume this ship and everything in it, right down to the last rivet--" * * * * * They walked down to the hold for another look at their uninvited guest, and almost wished they hadn't. It had reached the size of a small hippopotamus, although the resemblance ended there. Twenty hours had elapsed since the survey had begun. The _hlorg_ had used every minute of it, draining the tanks, engulfing dry stores, devouring walls and floors as it spread out in search of food, leaving trails of eroded metal wherever it went. It was ugly--ugly in its pink shapelessness, ugly in its slimy half-sentient movements, in its very _purposefulness_. But its ugliness went even deeper, stirring primordial feelings of revulsion and loathing in their minds as they watched it oozing implacably across the hold to another dry-storage bin. Wally Stone shuddered. "It's _grown_." "Too fast. Bowman charts it as geometric progression." Stone scratched his jaw as a lone pink pseudopod pushed out on the floor toward him. Then he leaped forward and stamped on it, severing the strand from the body. The severed member quivered and lay still for a moment. Then it flowed back to rejoin the body with a wet gurgle. Stone looked at his half-dissolved shoe. "Egotropism," Jenkins said. "Bowman played around with that, too. A severed piece will rejoin if it can. If it can't it just takes up independent residence and we have two _hlorgs_." "What happens to it outside the ship?" Stone wanted to know.