The Nitrogen Fix

by Hal Clement

  The Nitrogen Fix

  Hal Clement

  The Nitrogen Fix is a 1980 science fiction novel by Hal Clement. The plot revolves around a nomadic family in a future where all oxygen in the Earth's atmosphere has combined with nitrogen, so the atmosphere is mostly nitrogen with traces of water, nitrogen oxides and carbon dioxide, and the seas are very dilute nitric acid.

  The family is allied with an alien, an octopus-like being who can survive in the new atmosphere. Humans must live in shelters with oxygen-generating plants, or use suitable breathing equipment. Some of Earth's original life forms have mutated to survive in the changed atmosphere. Since almost no metals can exist in the corrosive atmosphere, any technology is based on ceramics or glass.

  Some humans are suspicious of the aliens, and even blame them for the change to the atmosphere, since they seem to be adapted for it. The family have an almost fatal encounter with a group of such people, who are holding another alien hostage. However, the two aliens are able to pool memories biochemically, so that they become the same personality in two bodies. Their combined knowledge and skills help the humans to escape.

  At the end the aliens reveal that they are basically tourists or scientists, and they travel from one system to another over thousands of years. Atmospheres "mature" when the nitrogen absorbs all the oxygen, the cause being the inevitable evolution of bacteria that use gold to catalyze the reaction. It is hinted, but not stated outright, that human mining of gold triggered this reaction.

  Hal Clement

  The Nitrogen Fix

  A distant second… but thanks

  1980 Illustrations by Janet Aulisio

  An ACE Book First Ace Printing: September 1980

  First Mass Market Edition: October 1981

  I

  Delivery, Delayed

  The golden brown sky was losing some of its uniformity with patches of darker scud starting to show to the west. There was still no wind, and the water was merely choppy, but Kahvi and Earrih were getting more and more uneasy about the kilometer which still separated them from the Canton shore.Milton Island was closer behind, but the cove on its south side would offer little protection if the wind really rose. The rafts, even with their present load, could not be sunk — Newell tissue was far too buoyant — but they could lose the cargo which had taken weeks to collect. The shelter between the Canton shore and the Sayre islets was looking more and more inviting.

  “You were right, Kahv. We should have worked around the shore; we could have spared another day or so.” Some of Earrin’s words were spoken aloud, but since his breathing mask muffled the more subtle phoneme distinctions, hand gestures conveyed much of the thought.

  His wife answered with a single, silent nod, not taking her eyes from the shore ahead for longer than was needed to read his signals. She got no particular thrill out of having been right; she had, after all, conceded the weight of the man’s arguments and had agreed to try the short cut. Risks always had to be taken; it was merely a question of which ones at any particular time. Spending more time out of reach of an air reserve could also have been dangerous.

  This time the raft assembly was much larger than usual and correspondingly harder to maneuver. The Hillers had been emphatic about wanting the very largest supply of metal and glass that could be obtained in two months. There had been no way to increase the rate at which the copper came in from the sea, but Bones had found enough glass on the harbor bottom to load not only the floats usually devoted to cargo but a dozen square meters of extra deck space. It was these new, rather hastily fashioned floats which were the main worry.

  Even in poling depth the cluster of rafts was awkward. Earrin and Kahvi had sometimes tried masts and sails, but neither knew anything significant about the art and had to depend on following winds. In deep water they usually used sweeps and Bones.

  At the moment the human couple were resting, with their sweeps trailing alongside. The Observer, however, was still at work; the tow lines extending from two of the bow floats were taut, and the raft was still moving slowly westward. If bad weather would only hold off for another hour or so, the cargo might be safe after all. If it didn’t — well, Bones could retrieve it from the bottom, but that would be unwise in sight of the Hillers. The group which had ordered this cargo seemed to have a very low opinion of the natives — there had been some mention of “Invaders” during the negotiations, though neither Kahvi nor Earrin had pursued that line of discussion.

  But there was no point in worrying about things which hadn’t happened; the important thing was action which would get them to the Canton shore and the jail as quickly as might be. Earrin was already taking up his long oar again. Kahvi did the same. The new child was not yet large enough to interfere.

  At least there was no wind against them yet. The foamy tissue rode very high, and the whole structure was much less affected by water currents by those in the air. Progress was steady.

  Both rowers looked over their shoulders to see whether the low clouds, colored by dioxide, were appreciably closer, but neither allowed their efforts at the sweeps to slacken, and gradually the shore grew clearer through the haze. The Blue Hills could still be seen to the south, which was a hopeful sign.

  Real storms, complete with rain and wind, were usually preceded by clouds down to the surface.

  This fact helped Kahvi to keep her hopes up; Earrin could not keep memory of the frequent exceptions to it out of his mind.

  Bones, under water fifty meters ahead, was giving no particular thought to the weather. Neither was the raft’s other occupant, playing quietly with her toys in the air tent and looking up every little while to see whether her parents were doing anything new. The transparent tissue of the tent let her see them clearly enough, though the two thicknesses of it between them rather blurred the adults’ view of each other.

  Danna had never in her memory been this far from shore, but was quite used to having the floats tossed even more violently than they were now, so she saw no reason to be afraid. Unless she was told to put on breathing gear, she would assume that everything was all right with the raft-and even then she would probably suppose it was only a drill. She was well along in acquiring the hang-ups needed for survival as a Nomad. She already knew how to check the bubbles of transparent tissue in which the Sparrel pseudolife produced breathing oxygen. She could even be trusted to warn her parents if the rise in tent pressure indicated that cartridge material was becoming saturated, though she had not been trustedwith the delicate task of bleeding off excess air. She was not, of course, strong enough to bring buckets of nitrogen under the raft to restore the tent’s breathing balance.

  She did, however, know smoke when she saw it, and it was Danna who called her parents’ attention to what lay ahead. Her voice came clearly through the tent tissue as the rafts drew within three hundred meters of the Canton shore.

  “Mother! Dad! Isn’t that a fire on the other side of the hill? The clouds are going up, so something must be hot!”

  Her elders stopped rowing and sprang to their feet, drawing the sweeps inboard by habit. They had been watching their goal, but had not looked carefully at the darkness above it. Neither could see, very clearly at that distance; their mask windows were of salvaged window glass, and their eyes middle-aged.

  Even after the child called the smoke to their attention, it was hard for them to be sure t at it was not ordinary rain scud. The ubiquitous oxides of nitrogen could be found in both.

  “She’s right,” Kahvi said at last. “There is a fire beyond the slope. “What are those Hillers doing?”

  “Maybe.” Earrin was less certain. “Let’s see what Bones can make of it. He has decent eyesight.” The man strode across the floats to the nearer of the tow lines and gave it a qu
ick double pull. Both ropes became slack at once, and a moment later the native, as the Fyns regarded the being, surfaced a few meters away. Kahvi gave the come-here gesture, and the child imitated her, though Bones would have had some trouble seeing her inside the tent. The creature plunged toward the raft in a series of dolphin-like leaps, the last of which carried its grotesque figure smoothly to the deck. For a moment it lay like a stranded fish; then the slender body curled upward until it stood erect, towering well above the human beings.

  The float supporting its hundred and twenty kilograms rocked irregularly in the chop, but the four lower limbs flexed to keep the body upright in spite of their fantastic slenderness and apparent frailty.

  Two of them framed the horizontal flukes which were used in dolphin-style swimming; the other two originated half a meter farther up the slender trunk and extended far enough sideways and forward to provide a trapezoidal support area quite large enough to make balance easy. From a little distance, where the tentacles were not noticeable, Bones would have looked absurdly like a fish standing on its tail, to anyone who had ever seen a fish. Kahvi and Earrin had not; their own species was the only macroscopic form of native animal life still surviving on Earth.

  The upper handling tentacles gestured a question, and Kahvi pointed in answer.

  “Fire, we think,” Earrin supplemented in the regular mix of voice and gesture. “You see better than we. It’s smoke, isn’t it?”

  “Yes,” a tentacle signified.

  “Do you remember what was growing on the other side, there? It is explosive? Should we go closer, or stay here, or go back?”

  “Not explosive, as I recall,” the Watcher signalled, “but of course it’s weeks since we were here.

  New things could have grown, especially with those Young Ones around.”

  “Do you really think they’d have that much influence? The normal Hiller would destroy anything that hadn’t been growing in the neighborhood for a hundred years.”

  “If they saw it in time,” her husband pointed out. “Something could have gotten ahead of them.

  But that doesn’t answer the question — should we risk getting closer, or wait until it burns out?”

  “It’s safe enough to approach, I judge,” replied Bones’ tentacles — the being had neither voice nor breathing equipment. “The floats are well varnished, and the tent tissue does not burn too easily. What growth I see on this side of the hill is mostly low-power, though there are a few blasters, of course.”

  “Are you sure?” asked Kahvi. “It looks to me as though nearly everything has become a shade lighter since we were last here. Couldn’t there be overgrowth? Or have you seen this before, too?”

  “No. You are right. There is overgrowth. I must withdraw my assurance of safety for the raft.”

  “And for the jail,” Earrin pointed out. “If fire gets there, we’d have to walk quite a distance to the next nearest air supply. I say it’s safer to get in there and clear risky plants away from the walls, if we can make it before the fire gets to this side of the hill.”

  “I see no people near the jail,” Bones commented. “There might really be none, or they might beinside and not have seen the smoke yet, or all be across the hill fighting the fire already. I agree; it will be safest to protect the jail even at some risk to the raft. It would take little to unroof that structure.”

  Without further gesture the streamlined form plunged back into the water, and a moment later the tow lines drew taut again.

  Inside the tent, Danna was looking hopefully at her parents. She understood most of the gesturespeech, but had evidently missed some of what had just been said. Catching her father’s eye, she picked up her own breathing kit and made an inquiring gesture. The parents looked at each other and nodded. Dana’s happy grin disappeared behind her mask.

  Kahvi and her husband resumed rowing, but both kept more attention on the child than on their goal for the next few minutes. Danna had been carefully brought up, but they would not have allowed her to get dressed for outdoors unsupervised any more than either of them would have allowed the other to do so.

  The little one finished donning the acid-tight shorts, halter, and face mask. She slung the oxygen and absorber cartridges between her narrow shoulders, stood up, and turned slowly around for inspection.

  Not until both parents had nodded approval did she step to the space where a float had been omitted from the deck structure, and slip into the water Both parents counted subvocally, but long before the twelve seconds which would have justified action had passed, the five-year-old’s head showed through the other opening in the deck.

  She slid out of the water as smoothly as Bones; she had been swimming since before she could walk.

  “Did Bones say it was a real fire?” The child was speaking as soon as her head was out of water. She used more words and fewer gestures than her parents, since her voice penetrated the mask better.

  “It must be big. Why are we going closer? Can I row too?”

  “Bones doesn’t know what’s burning, but it is a big fire,” replied her mother. “It may be dangerous, but we have to go close enough to save the jail — the air place on shore — in case the fire gets close to it.

  It will help if you row, but you must stay here when we get to shore. You’ll have to take care of the raft and the tent, in case any sparks — little pieces of fire — fall on them. You have buckets ready and spill them on any fire that comes. If it doesn’t come, it will be good to spill them on the tent anyway; if it’s wet the fire won’t hurt it. All right?”

  “Sure.” Danna picked up her small oar, went to her regular rowing station, and began to pull. It was doubtful whether Bones could feel the effect, but she put enough strain on the oar to feel useful.

  The wind still held off, but as they approached the shore smoke came drifting to meet the raft.

  Danna looked over her shoulder at it occasionally and Kahvi could see that the child was uneasy.

  Neither adult, however, felt seriously concerned as long as the fire itself could not be seen, and their calmness kept the little one from panic, though she had been told so much about the dangers of fire.

  Fifty meters from shore Bones form appeared, rearing up from the water and evidently standing on the bottom. The lines were still taut, but the human beings took the hint and stopped rowing.

  The raft could not be brought ashore, since there had to be swimming space under it to enter and leave the tent. Bones had no need for air, but had been with them since before Danna’s birth and knew some of their physical requirements. One of the great eyes rolled back at the raft, while the other continued to watch the smoke, much heavier now, as it continued to jet upward from beyond the low ridge two hundred meters away.

  There had been no explosions, but this was only mildly encouraging. Many plants contained both reducing tissue and nitrates, arranged with varying degrees of intimacy. They burned with varying rates when something did light them; the nitrogen real-life mutated so frequently and grew so rapidly that one could never be sure just what an apparently familiar type would do. Pseudolife was far more reliable, but there was little of that in sight.

  “Nothing I can see is burning,” Danna said after looking carefully. “Do you think the fire will really come over this way?”

  “We can’t be sure, so we’ll have to watch,” her father answered. “Your mother and Bones and I will all have to go ashore as soon as we’re anchored to clear plants away from the jail or do whatever else is needed to keep it from losing its roof — stone won’t burn, you know. You’ll have to take care of home,here.” The child nodded, and tried to put on a firm expression under her mask.

  Bones had pulled the raft in almost to the proper depth, and now gestured that the anchors should be dropped. The adults went aft, and each lowered one of the tent-tissue sacks of boulders into the water.

  Danna tried to get the bow anchor overboard, but its hundred kilogram weight was far too much for her.

&n
bsp; Bones took a step toward the raft and eased the bag off the float; the child plunged in after it and swam along as it was borne a dozen meters shoreward and set firmly on the muddy bottom. Then Bones plunged back past the raft and positioned each of the other anchors in turn, the human beings paying out enough line to allow for the tide. Danna remained in the water trying to help until this job was finished; then a green-and-brown tentacle curled about her waist and lifted her, laughing, back to the deck beside her parents. They joined in the laughter for a moment, and then reached for the tools stacked beside the air tent.

  “Get the buckets and keep the tent wet,” the mother repeated. “We’ll be able to hear you if you need us, and will watch, so don’t be afraid.” Kahvi plunged from the bow carrying a hoe-like implement of wood and glass. Her husband followed with a long pole carrying a sponge at the end.

  Bones was already halfway to the beach. The others had no chance of catching up with the creature either swimming or running, but in a meter or so of water-too shallow for Bones to swim, too deep for the tentacular legs to work freely-they gained, and were close behind by the time they too had to wade.

  The beach was slimy with nitro-life, which was (they hoped) too wet to be a fire hazard, but made running difficult. The larger growths were mostly of the smoldering type as far as they could see, but there was an occasional blaster among them.

  As the party reached the base of the little peninsula to the south of their anchorage, with the jail some forty meters ahead and inland, there came a thud which was felt rather than heard. A fountain of red-hot coals rose into view from the other side of the ridge, spread slowly with eye-arresting slowness, and descended again. Some of the glowing fragments landed quite close to the watchers and even closer to the building, and any doubts about the nature of the bushes were quelled as half a dozen of them, struck by the coals, began to smoke and glow. There was no flame, since there was practically no free oxygen to react with the gases being distilled from the plant tissues; the latter burned at all only because of their nitrate content.