The Nitrogen Fix

by Hal Clement

  “Toss,” she said quietly.

  The ceremony took only a few minutes. Seven goes were tossed before everyone had been touched, but there were no complaints; all were used to the method.

  “I’m coming, too,” Genda said abruptly. The others merely nodded; regardless of their preferences, she had the right to come if she pleased.

  However, it was nearly two hours before the group was outside. Most of the time was spent in a large room with a huge map of the Blue Hills area which Earrin and Bones did their best to memorize, while assignments to the various jails and agreements on where and when to meet were made.

  Once through the lock, most of the family groups went off in different directions toward their assigned buildings. All were carrying supplies of the appropriate spores or pseudolife fragments. The teachers, their ten-year-old Betty, Genda, Earrin, and Bones-Two started the three kilometer trip northward toward the raft. It was fairly late afternoon, but they hoped to reach it before dark. Genda walked silently, but kept her eyes roving over everything they passed. The child asked almost constant questions which were answered usually by her parents but sometimes passed on to Earrin or even Bones. The Nomad said nothing except when answering or interpreting; he was learning quite enough without steering the conversation.

  Genda suddenly stopped and pointed. “Look!” she snapped. “Those young creatures have been making new life forms, too.”

  Earrin was curious. “That’s just a Newell block,” he said. “They’ve been around for years. You folks are always making variations; what’s wrong with that? I’ve bought lots of new kinds of food and air plants from you Hillers over the years.”

  “Taking advantage of natural changes is one thing. Making something entirely new involves the Evil.”

  “But what’s new about this? It’s grown for long before I was born — years — around some of the cities. My raft is made of it. I sold a piece to you people three or four years ago for a very nice milk plant. I don’t know why this one is growing here; it may have been planted on purpose, or someone accidentally dropped a piece. It’s been here for several years, certainly — it’s big enough almost to make another raft.”

  “You mean it’s natural?” Genda was unconvinced.

  “I don’t know, but I doubt it. It seems to have no natural enemies, and almost completely stops wing when it reaches about four cubic meters.

  Pseudolife was planned that way to minimize the risk of its spreading out of control, you know. You haven’t been outdoors much, have you? I know there are other samples of this stuff growing around.”“I haven’t seen any,” was the rather evasive reply. Fyn didn’t press the question; Zhamia and her daughter looked at each other and barely managed to conceal their smiles.

  They were now on the south slope of the last hill which barred their sight of the raft, and when they topped it Fyn was relieved to see that his home was still there. He was less happy to see a dozen people busy around the site where the cargo had been left. Just shoreward of this point was something which had not been there before. It was a dome-shaped structure fully ten meters across and half as high.

  Earrin had of course never seen an igloo, so the resemblance escaped him. He was not yet close enough to see the panes of glass among the spongy block of Newell tissue, but two or three of these windows were so placed as to reflect sunlight toward the newcomers, so their nature could be guessed.

  There was no way to be certain that the workers were members of the Hemenway group, but it seemed likely. Fyn, after a moment’s thought, turned to Bones.

  “Get into the water before these people see you, and wait at the raft. If Kahvi or Danna are there, tell them what’s happening. These are probably the same people who were interested in finding out how to kill you.”

  “They are. I recognize some of them,” the Observer gestured. The slender form promptly made its way back down the southeast side of the hill, and slipped over to the water. The human beings resumed their walk toward the jail.

  They were not seen until they were almost at the building; then one of the masked workers looked up, and immediately called to the others. As had been agreed, Zhamia and Genda went at once to the air lock with their supplies of nitrogen producers, while Mort, Earrin, and Betty went on toward the new structure. It was understood that if anything even slightly suggestive of violence were to start, the women and the child were to run back toward the city at full speed, while the men did what they could to delay pursuit. Neither of the men actually believed that anything of the sort could happen, but Bones had by now told of the glass caltrops.

  Earrin would have preferred to check with Kahvi before talking to this group, but it seemed unwise to head for the raft right now. Maybe she would see him and come ashore to help.

  And maybe she wouldn’t. Behind the approaching Hillers, now close enough to recognize individually, a short distance out in the water, the figure of the smaller Bones suddenly appeared and stood upright. It was close enough for even Earrin to see clearly. There was only one likely reason why the being had not stayed at the raft as requested, and the message sent by the gesturing tentacles was no surprise. “There is no one on the raft.”

  The native promptly disappeared again.

  XVI

  Action, Antagonistic

  Neither Kahvi nor Bones had made any plans for such an event, but both acted as though there had been careful rehearsal. The woman did not even slow down, but hurtled with her full running speed into the man who had suddenly appeared in her path. This unfortunate had heard her voice as she called to Bones, but had not seen her in time.

  He was therefore not braced for any impact, and went over backward. Even worse from his viewpoint, Kahvi had crossed her arms in front of her body and. taken the force on her elbows in an almost instinctive gesture to protect the baby.

  The man’s ribs were not actually broken, but it was some days before he was sure of that. His immediate trouble was landing in the glass-covered area, flat on his back. His howl warned the woman, and since the collision had almost stopped her anyway, she was able to keep her feet out of the caltrops.

  Bones, fully aware of the location of the glass, made even better use of the incident; the body of the guard, writhing though it was, made an adequate bridge. It was too dark to signal to Kahvi, but communication was not needed. The woman snatched up Danna, Bones pulled the sandals from the feet of the guard, and they were off down and around the hill. Kahvi confessed afterward that she had beentempted to stay and trip some of the others into the glass, but admitted she was glad she hadn’t. The shrieks of the single victim, fading as they fled, did not provide the anticipated pleasure. She felt sick again, but managed to keep it under control.

  Neither she nor Bones could tell whether they were being pursued. Some, judging by the voices, had stayed to help the guard, but others might be following. It seemed unwise to wait to find out.

  They paused briefly while Bones took over Danna and gave the sandals to the woman. She fastened them on after some difficulty, and they went on. Kahvi was leading the group around the hill toward the west; her first months as a Nomad had been passed mostly on that side of Great Blue Hill, and she was certain of finding a breathing refuge there.

  Her cartridges and Danna’s still had many hours in them after their recent pause in the other jail, but some Nomad decisions were without detailed thought. Her goal was reached with the raft, but she would not head toward it without checking on possible pursuers; and she would not make that check without being close to a breathing refuge.

  They were travelling slowly now, even with Bones carrying the main burden. Kahvi was not worrying about glass as long as her feet were protected, but she was tired and half way through a pregnancy; and the best of breathing masks interferes with activity.

  They came finally to a jail on the northwest slope of Great Blue Hill, which suited the wornan’s purpose. Kahvi led the way to a thicket of realwood on the farther side of the structure, and all concealed
themselves inside. Danna went to sleep in a hastily assembled nest, and Kahvi devoted some time to exchanging information with the Observer. While doing this, however, she looked frequently back along the way they had come.

  Presently the moon was high enough to illuminate the landscape plainly, and drown out the faint light which had been visible through the roof of the jail. As it grew brighter, two figures appeared on the shoulder of the hill where the trio had traveled. They were walking slowly. Kahvi, with no tracking experience, did not guess at the reason; she assumed that they had followed by sound, and wondered why they had taken so long to arrive.

  The pursuers saw the jail as soon as they reached the near slope. One pointed, and their speed increased. One of them waited a few meters from the air lock while the other quietly circled the building; then they approached the lock together, and one of them entered.

  To Kahvi’s surprise, conversation sounded from the building almost at once. It hadn’t occurred to her that there might be someone already inside. The waiting pursuer also seemed a little taken aback, and after a few seconds of listening he, too, disappeared through the lock. Kahvi, uttering a quick “wait here” in words only, and hoping that Bones would understand, dashed to the near wall of the jail and was at the top in seconds.

  Eavesdropping had been useful before and was certainly worth trying again. As before, she was careful about moonlight and gold jewelry. This place was better lighted inside. The two who had just entered were easily recognizable, since they were dripping wet. The three others appeared to form a family group; they were a man and woman somewhere near Kahvi’s own age, and a boy of nine or ten.

  This was not too surprising; Kahvi knew that both custom and law in most cities worked toward a tight family knitting.

  Parents were expected to take active part in their children’s education, and be with them whenever anything important or dangerous was due to happen. It was quite understandable that the parents would be outdoors if the child had to be.

  It was much less obvious why the child had to be out, but Kahvi gave little thought to the matter; there was a much more interesting difference between the groups. The newcomers had promptly removed their masks, but the family, who had evidently been inside for some time, had theirs on. There was an obvious explanation; it really qualified only as an inference, but it seemed a very, very strong inference.

  This jail must be oxygen-loaded, too. There must be a surprising number of oxygen-junkies in Great Blue Hill; what had been happening to the city since Kahvi had been Nomadded, anyway?

  There was still more to be inferred. The family members were normal people, and they knew aboutthe changed air. The conversation came as no surprise. One of the newcomers was speaking.

  “How did you know about the oxygen? Don’t tell me you could smell it!” The masked adults shook their heads negatively, and the man replied aloud.

  “Of course not; but look at the trays. Every last one of them has Bence or Trendell growths-makers.

  There isn’t a nitrogen maker or dilution tube in the place.”

  “You noticed that as soon as you got here?”

  “Of course — Who could be sloppy enough not to make that check in a new building? I’m glad to say that Ray, here, was — ” The other cut in.

  “You weren’t expecting something of the sort, were you.? Why are you here so late at night?”

  “Well,” the father admitted reluctantly, “as a matter of fact, yes. We’ve checked several buildings.

  We — ”

  “Never mind softening it. You came to check the air, on purpose?”

  “Yes.”

  “Why? And you say you’ve been to others?”

  “Yes, several. It was reported that many of the safety buildings had been sabotaged by oxygen wasters, and a lot of families came out to make repairs.

  Both newcomers stiffened, and the one who had hitherto been silent asked quickly, “You brought N-cultures with you?”

  “Yes, of course.”

  “Have you spoiled any of the O-plants yet?”

  “We’ve fixed them, yes, of course. It was the first thing we did. Of course it will take a while before the air becomes normal, so we’re staying masked for the night.”

  The two looked at each other, frowning. One seemed uncertain; the other was more organized.

  “Which ones did you fix?”

  The woman answered after a moment’s hesitation, “We’re not exactly sure — it didn’t seem to make much difference, so we didn’t pay a great deal of attention.”

  “You’re a liar!” was the snarled answer. “With three of you doing it, you’d never have left it to chance who did what. You’d never have risked destroying them all!”

  The husband straightened up indignantly. “Watch your language, waster. There was no danger of doing them all; our N-spores couldn’t grow in a Bence culture. We probably did do all the others, if it’s so important to you. We don’t lie, and if you think anyone would on such a minor matter please get out of here — you’ll be giving the boy dangerous ideas, though I’d trust him not to be much impressed by your kind!”

  “Breathe it! Don’t tell me you’d spoil all of even one of the cultures. Even if you’re stupid enough to think that your masks will keep extra oxygen out, you can ‘t be dumb enough to risk the last of any culture.” He laughed at the expressions visible even with the masks in place. “Deep thinkers, aren’t you?

  All a rebreather bellows does is mix the gas from your cartridge with some of the outdoor air. You’re like a couple of Nomads — follow the rules without any thinking!”

  “Good for them!” retorted the woman. “At least, they know about rules. It was a Nomad who told us about the vandalism in the jails. I’d rather look like one of them than be mistaken for one of you if-a-little-is-good-more-is-better types. Now get out of the way. We’re leaving.”

  The taller of the addicts was wearing an unpleasant smile. “Sure. Two of you go any time you want.

  The kid stays until we know just which O-plants you heirs of righteousness ruined.”

  “You can’t stop him. We’ll — ”

  “You’ll what? Even if you count him, the three of you aren’t strong enough to get past us without having your masks ruined. Think it over. Lots of spare cartridges here, but only a few masks, and we can take care of those before you can save them. It’s so much easier to smash things than to fix them, isn’t it?”

  Before either parent could move he had taken two long strides to the small boy, and seized the tubes running from cartridges to bellows. “Shall I pull?”

  “No!” the mother almost shrieked.

  For a moment, the watching Kahvi didn’t know whether to be more indignant at the junky’s threat orat the mother’s lack of firmness. Then she imagined Danna in the boy’s place and understood. Decision was a little more difficult than usual, but having decided, Kahvi’s action was of course unhesitating.

  “It won’t do you any good!” she called, rising to her knees on the wall. “There’ll be plenty of others along tomorrow. You junkies may as well let them all out, and enjoy what you can of your oxygen. If it takes the others long enough to get here, maybe you’ll be able to see which of your plants got fixed. But leave that boy alone, or we’ll come in there now and make you sorry. Bones! Danna! Come over here and cover this air lock!”

  The people in the jail looked up in astonishment at Kahvi’s figure, clearly visible in the moonlight. The addicts, startled, did nothing else; the parents seized their son and plunged into the lock pool.

  They emerged outside just as Bones arrived with Danna, and at the sight of the Observer and its burden they froze almost as completely as the two still within. Kahvi’s voice restored them.

  “All right, don’t worry about Bones. She’s working with me, and I trust her with my daughter. Leave your boy outside, and come back in with Bones and me. There’s work to do.” She shifted to sign language, letting Bones know her plans, and the native set Da
nna down beside the other child.

  Kahvi descended, a little awkwardly, from the wall and led the way to the lock. Bones followed immediately, the other pair farther back and more hesitant. By the time they were inside, most of the action had finished.

  Bones, at a gesture from the woman, had seized the two men, holding their arms at their sides with ropy tentacles. Kahvi was busy scooping up masks and cartridges. She gestured at the other to do the same, as they wiped mask windows.

  “We’ll leave a few cartridges, of course, but be sure to get all the masks — no, we’ll leave one,” the Nomad said briskly. “If something happens to the roof they can stay alive by sharing it, but won’t be able to get into mischief. You two — ” she addressed the prisoners “ — can play around with the cultures all you want, but I’d suggest you be very disciplined. If you spoil any more oxygen, you might just have to get to the next jail holding your breaths by turns. As I remember, it’s about five hundred meters a little south of west, over two hills. Use your judgment, if overloading yourselves with oxygen has left you any.”

  One of the addicts answered. “Very nice, Nomad. We know how pure and righteous you all are, and of course you have every right to force other people to go along with your morals. You must feel really virtuous, going around with an Invader. I suppose you’ll help it destroy the cities the way they did the rest of the world — you won’t be bothered, will you?”

  “No time for mythology just now,” Kahvi replied briefly. “If you feel the need for straight oxy, at least you could build your own gas-houses.

  These buildings were made to save lives, and I haven’t any time to waste on free-loaders. Got everything, you two? All right, Bones — ” she shifted her burden to one arm and gestured with the other — ”hold them until we’re outside with the children. Then do anything you can think of to keep them from interfering with you, and come along. We’ll head for the raft; we have plenty of air.” She started down the air lock steps, then turned back. “One more thing, now that I think of it. These other folks are barefoot, I notice. I’ll take your sandals. I don’t like those nasty bits of glass you oxy-lovers have invented.”