Stephanie Ilogu knew the Southern Ocean was supposed to be cold. Lars had been battling to cool the ocean since Stephanie was seven years old. If my teeth chatter, I’m disrespecting my husband’s success.

Maybe I wouldn’t think so much about my numb feet and face, or the dank sogginess leaking into my hair through my watch cap, or how much cold air leaks in under this huge parka, if I had something to do besides listen to my husband and his ex-wife make history together, so I can write about how great they both are.

Lars had warned her about his ex’s enthusiasm. “Bigger than Brazil in less than three months!” Nicole leaned far out over the railing, risking a five-meter plunge into the dense mat, which looked like floating spinach. Below the first surface meter, black, oily fibre extended forty meters down, so dense and deep that the Southern Ocean’s surface was nearly flat despite a face-stinging headwind.

Lars wore his parka hood up, and from behind him Stephanie could not watch his expression as Nicole arched her back, revealing Greek-statue glutes under glistening skin the colour of hot chocolate. Twisting tightly at the waist, she grasped the sampling pole beside her, hooked heel behind knee around the rail, and dangled over the green, motionless, freezing sea.

She wore her thin one-piece bathing suit for company or cameras and no other reason. Naked except to broadcast, Nicole had walked on Mars, swum under the ice on Europa, and spent four years outdoors in methane snow and slush on Titan. If Nicole fell into the slimy cold mess below, to her, the icy sea that could chill a human to death in minutes would call for a slight speedup of her fusor. She could then tread water for weeks, swim north to Cape Town, or walk on the sea floor to Davis Antarctic Station.

Nicole whipped up in a back flip and lighted as neatly on the ice-coated deck as if she’d been wearing sneakers on a dry sidewalk. Stephanie reminded herself that those bare toes had dealt with far worse.

Nicole peered through the sample jar. “Mat’s still spreading outward at eighty kilometers a day. And if this sample is like every other one, there’s more genetic diversity in this jar than we’ve found in the solar system up till now. The million new species we’ve catalogued have DNA less like anything on Earth than a Europan tentacled clam or a Martian braidworm. The ocean still has surprises! I love it!”

“I hate surprises,” Lars said. “Surprises are what good management is supposed to control.”

“I love surprises,” Nicole said. Her huge grin invited Stephanie into the conversation. “No surprises, no news media, no job for Steph. And the sea should surprise us.” Her sweeping, circular gesture embraced the horizon; Clarke’s bow cut ceaselessly into the featureless plain of mat, stern jets churning a darker path that closed up in less than a kilometer. “Science is about knowing enough to know what’s just uncommon and what’s a real surprise. Most people are —”

Clarke cleared its forward intake screens. An immense stream of green and black mat shot upward and forward, sounding like God’s clogged toilet clearing. The headwind blew the plume, the colour and texture of black bean and broccoli soup, back onto them.

“I think we’re done, for the moment,” Lars said.

Just before going below, shivering and holding her breath against the stench like rotten fish and cabbage, Stephanie looked back at Nicole bobbing for another sample. Her beautifully muscled legs wrapped around the railing in a figure-four; beyond her upward-reaching feet, all the way to the horizon, the Southern Ocean was a bright green sheet in the clear wet sunlight.

Stephanie usually liked undressing in front of Lars, but the fresh memory of Nicole, her body as fine today as when it was built, made her hesitate. Lars grabbed the hem of her parka and pulled it up over her head, stripping her into the refresher slot until he knelt to remove her safety boots. “Now you do me.”

The freezing, stinking seawater that had drenched him spattered onto her as she removed his parka, but she didn’t mind when she saw the smile as his gaze caressed her.

He gently stroked her hair, forehead, and cheek, his hands still warm and damp from his glove. “She has too many muscles,” Lars said, reading Stephanie’s mind, “and not enough colour contrast.” He folded his all-but-paper-white fingers gently into her deep brown ones, where she had been caressing the forearm stroking her cheek, and guided her hand to the back of his neck. His hand returned to her cheek, and trailed down along her neck, and over her collarbone. “See? An old poop like me needs high contrast or he’d never be able to find his way around. Now let’s boil the stink and cold off ourselves.”

In the roaring hot shower, she scrubbed his shaven head fiercely, the way he preferred; he relished lathering her and rinsing her off. When they had washed and kissed enough, he said, “Well, now at least we don’t reek of spoiled sardines.” They towelled each other off in the small space between the bed and the closet, close enough to feel each other’s warmth. “I’m feeling a little more secure,” Stephanie said. “It’s just — oh, everything. She’s so beautiful.”

“They built her that way,” Lars reminded her, “because they thought the planetary exploration program would be more politically sustainable if the people out there doing it could attract fans on Earth. And my god, they were right. We had a hell of a fight to bring the six of them back to Earth and put them on useful projects; even today almost half the population wants to watch new exploration shows with the humaniforms bouncing around on some useless rock out in space.”

“It makes me think she’s not really human,” Stephanie said. “You took away everything she was made for and everything she lived for — yet she came back here and married you. That’s not a person. A real person couldn’t do that.”

“A person without much choice can do all kinds of things.” He fastened his clean tunic. “We married each other to establish that the six of them were persons and citizens. Otherwise the corporations would’ve used humaniform technology to make billions of slaves. Can you imagine beings like Nicole spending six hundred years as a nanny, a butler, or a sex toy?”

“She says she likes to work.”

“She likes to exercise her abilities, which are those of a very capable oceanographer and marine biologist. She’ll enjoy figuring out why all this crap is growing in the ocean —”

“I wish you could just order her to fix it.”

“As a bureaucrat, I might like that, but as a person who was once married to that person, I don’t want obedience, I want her best work, things I’d never have thought to ask for that solve problems I didn’t know were problems.”

“But you hate surprises. And she has every reason to hate you and you don’t know why she’s helping instead.”

“I was a reasonably decent husband for a guy who started late without a clue. As for why humaniforms live with us, work with us, and don’t seem to be too pissed off that we took them away from the environments they were made for — well, they seem to like us. They’ve all been married to plain old biological people. Nicole herself has had two husbands since me. She’ll probably have a good solid twenty more, in the next few centuries. She likes people. And you’d have to be a jerk not to like her, once you get to know her.” He hugged Stephanie. “Look, she’s beautiful, she’ll live a long time, and she can go places we can’t. Otherwise she’s about as superior to us as a really great athlete combined with a pretty smart scientist. Haven’t you ever met any humaniforms before today?”

“No, I haven’t. Think about it, Lars, when would I? I got the reporting job straight out of school, and by that time you were already courting me. My parents were high level bureaucrats in West Africa, which isn’t a very important province; it was just Dad’s good luck that you knew him from school, but we weren’t anywhere near the social level where the humaniforms circulate. And I’m not sure I’d have taken the chance to meet one if I could. To tell you the truth I’m scared of them. They creep me out.”

“All right. Well, you’ve got the biggest opportunity of your life right now, to report this story.” His voice was strangely cold; the small and frightened person inside her could not turn to him for the usual comfort, and she felt horribly alone, looking into his matter-of-fact, judging eyes. “So you can bail on the opportunity, right now, and I’ll find someone who can talk to Nicole to record this story. Or you can get over feeling ‘creepy’ and talk with her. Drop the job or drop the feeling, Stephanie.”

He’s scared I’ll drop the job. That decided her. “All right. I’ll learn to deal with her.” But she’s so beautiful and Lars slept with her for ten years. A ten-year marriage couldn’t have been just to prove a legal point, a month would have done that. Why didn’t I realize that till now? “At least I’ll try.”

He looked like he tasted something bad. “You’re meeting a remarkable person, not undertaking an ordeal. Have you paid any attention to any accurate source about humaniforms or just to the junky, scary stuff in the media?”

That hurt. “Lars, okay, obviously you think I’m a bigot or a phobe, so what should I know about Nicole?”

“Mostly how much she’s like you — smart but not freakishly smart, with more empathy, emotional stability and sense of duty than most people have. That fusor in her chest, her ability to adjust her sensations to stay comfortable and sensitive, that body made of materials that tolerate very wide temperature and pH ranges — that’s a spec sheet, that’s not her. If you prick her, she won’t bleed, she’ll block the pain. If you tickle her, she’ll laugh because she likes to laugh. She’d be hard to poison but hydrofluoric acid would work, and she’d die.”

“See, but what bothers me is, ‘And if you wrong her, shall she not revenge?’ Lars, you took away the job she loved and was born to do, and —”

“You’d feel she was more of a person if she said, ‘All you fleshy bastards can just die?’”

“Maybe.” Stephanie sighed. “I still think of her as a fast computer running smart software inside a tough, pretty mannequin. I wish she’d never —”

Nicole knocked on their door. “No need to come up on the deck but there’s something you urgently need to see.”

They wore their parkas hood down and without hats through Clarke’s unheated corridors, but slipped out of them in the bathygraphy room. “It’s easiest to see on the combined display, over here,” Nicole said, “but the truth is it’s so plain that a World War II destroyer’s sonar could have picked it up. All the meson scanning, x-ray boundary analysers, and phase-shifted sonar just add more vivid detail. Now just look.” Stephanie leaned forward to peer into the holographic barrel.

Beside her, Lars said, “What the hell are those? And how big are they?”

Stephanie found the scales and legends. In an almost perfectly circular area about four hundred kilometers across, a bull’s-eye in the much bigger circle of mat, arranged in equilateral triangles about a kilometer and a half on a side, towers two kilometers high and a hundred meters across reared up from the ocean floor. “Hunh,” Stephanie said, “how big is a redwood?”

“Good comparison,” Nicole said. “Because up at the top these things, that green mist in the holo, represent crowns — or one big canopy, I guess — of filaments, some as thick as your thigh, some thinner than your hair,” Nicole said. “At a guess, they’re the roots for upside-down trees.”

“Upside-down trees?”

“Well, not trees per se, but that canopy looks like a feeding structure attached to those trunks, if that’s what you want to call them, and since it’s all more than a kilometer below the surface, it’s not leaves. So a trunk with roots on top is an upside down tree, at least till we have a better name. Anyway, I’m going to swim down and have a look.”

Lars looked like he’d been kicked in the stomach. “You most certainly are not —”

“I’m not under your direction,” Nicole pointed out. “And I want to know what’s going on down there, and I’m more capable than any robot. I’ll just throw my deepwater bag together, and dive.”

Lars looked up at the ceiling, thinking. “The publicity situation is already a mess. If we wait for a robot, that will look bad, but if we lose one of the best-loved humaniforms, it will look worse. We have no idea what’s going on down there, and if we let you go —”

“You won’t be letting me anything,” Nicole said. “I’m a citizen, my contract is with the Oceanographic Institute and they have a separate one with the company that operates Clarke. Nothing stops me from just going over the side. Do you want to have been consulted or not?”

“I do,” Stephanie said. “Time for an interview before you dive in?”

“Sure,” Nicole said. “Well, Lars, do you want your wife to write that you were dithering?”

Lars shrugged. “It’s something to do while everything spins out of control.” He stared down into the holo image of the huge structures on the bottom of the ocean, squeezing his lower lip between his thumb and forefinger. “A surprise with big stakes and a good chance of guessing wrong. I hate those.”

Nicole looked away. “Stephanie, I know it’s miserable for you up top, and once I’m up there I’m just going to dive over the side, so if you don’t mind sitting in a corner of my cabin while I pack —”

“If I can stick my autorec to the wall —”

“Sure. Then just run up with me to shoot vid of me going over the side. You’ll only have to be out in the freezing weather for a few seconds.”

Nicole’s cabin completely overthrew Stephanie’s expectation of Spartan pragmatism. Space she saved by having no clothes and needing no bed enabled a wild chaos of piles of books, tools, instruments, and papers. Every wall was covered by paste-on screens, displaying a rotating profusion of scenery from all over the solar system, pictures of ex-husbands and families, major awards, and the other five humaniforms. The physical chaos of the floor was exceeded only by the informational chaos of the walls. Stephanie had to smile.

Nicole said, “What?”

“Oh, just noticing that this is a place where somebody works with a passion,” Stephanie said. That I didn’t expect from a robot.

Nicole nodded. “I wish I’d been designed to sleep; night watches in here are lonely. I think that spot by the bathroom door will work for your autorec. Fire away.”

Tip her off guard. “Do the oceans ever bore you?”

“I’ve been down in every ocean the solar system’s still got,” Nicole said, “and walked the dry bottoms of the ones that’re gone, and a thousand years would not suffice to see just the cool parts of one.”

Great answer, they’ll quote that everywhere. Now the bread and butter. “For the record, what’s going into that bag and what are you going to do?”

“Sampling tools, suction gadgets to capture fluids, blades and drills for solids, containers for everything. Acoustic, gamma, meson, and positron scanners. I’m going to strap lights on my forehead and forearms, fill my lungs with diving fluid, turn my temperature up, and dive down through the canopy. Then I’ll cut pieces off these upside-down trees, drill holes, bring back stuff to analyse, and look around in general.”

“Any idea what you’re going to look for?”

“I’d like to know where all the sea life that was here went,” Nicole said. “Because of the iron fertilization, there were immense populations of everything from microbes up to whales around here, and there haven’t been any migrations or any population increases in the adjacent uncontaminated areas. Maybe two million marine mammals and six billion fish and sharks are gone, and god knows how many invertebrates, along with four hundred billion tons of plant life. I’m pretty sure they’re dead, but where are all the bodies?”

“No idea?”

“Biomass is energy and whatever that is down there required a lot of energy to make. Beyond that, I try to keep an open mind and just tell the world to surprise me.”

Another great answer. Now something for the personal interest. “Here’s what people are going to ask me — what’s she really like?”

Nicole slipped the last tool into the bag and started strapping a utility light and tool holster to her left arm. “Hunh. I really like surprises, the deep, wild, turn-over-the-world kind. I do know what you mean, but honestly, how would I know what I’m like? That happens out there with everyone else, and in here, there isn’t anyone to compare to.” Nicole hesitated, looked at her directly, and said, “You’re not very comfortable talking to a humaniform, are you?” She pulled the lighted helmet onto her head and fastened the chin strap.

“Have my questions been too blunt?”

“Well, many times, people talk to me bluntly for the same reason they talk to any machine bluntly, because it’s not a person,” she said. “People swear at a screwdriver because they don’t care what the screwdriver thinks of them.”

Whoa, that one made me squirm. Turn it around. “And you do care what I think of you.”

Nicole nodded, as if reaching inside herself for the answer. “I do; I usually care what people think of me.”

“That’s a pretty good argument that you’re a person. Welcome to the club.”

Nicole surprised her by laughing. “Wow, I’m oversensitive today, and not in a way I can adjust.” She stepped carefully over a couple of construction-block-sized instruments and surprised Stephanie with a warm, tight hug.

I’d’ve thought she’d feel like a heated couch, but this is nice. She stroked the bare skin of Nicole’s shoulder: like nubbly fabric, softer than raw silk but not as slick as satin. Stephanie felt at once that Nicole’s skin was as sensitive, as responsive, as easy to feel as her own. When Nicole kissed her cheek, the lips felt warm, and slightly rough. “We’ll be friends. You’ll see. Right now I have to run.”

“Of course. Don’t let me use up your daylight.”

Nicole smiled, shaking her head. “Now, as a reporter —”

“Duh, of course, it’s always dark down there.”

Out on the deck, Stephanie recorded Nicole putting the tube into her mouth and inhaling diving fluid; it looked like watery brown pudding. Then Nicole calmly stuck the needle into her abdominal cavity, then her sinuses, filling all with the same goo. She had body cavities to give her a normal speaking voice, to process repair materials in the field, and be normally proportioned without having to haul excess weight; for ocean-bottom work, being fluid-filled prevented her from collapsing.

Filled with fluid, Nicole couldn’t speak, so she waved with a merry smile, and flipped over the side in a dive. The big splash flung up green and black gunk, which slid down Clarke’s side. Alone and cold, Stephanie went back below.

“How’d it go?” Lars asked, after they had both been quietly working in their cabin for more than an hour.

“I think it’s going to be easier than I imagined,” Stephanie said. “You’re right, she’s hard not to like.” The memory of Nicole’s warm, different texture, and the strength of those arms holding her, was distracting, but very pleasant.

They had eaten dinner, and darkness had long since fallen, when texts popped up on their screens. Nicole had returned, and they would meet her in the conference room with the other scientists in twenty minutes. “I bet she doesn’t want anyone recording how she removes diving fluid,” Stephanie said.

“Nicole always said she felt about it like human women feel about changing a tampon — no big deal but too messy for public. She can collapse each cavity completely in one stroke, so in three quick motions, she clears her lungs through her mouth, her sinuses through her nose, and her abdominal —”

“Gosh, I’m looking forward to her presentation.”

At the meeting, Nicole looked like the kid who just had a perfect Christmas. “All right, I’m scared and worried, and I’ll explain why in a second, but what I just found is so awesome — like in the really old sense, the way Nix Olympica is awesome — that I hope you’ll forgive me for babbling. First of all, those vertical structures are mostly made out of calcium hydroxylapatite, with a highly complex internal structure.”

Someone said, “Bone.”

“Exactly. The towers are gigantic bones. The root-canopy above is a huge digestive organ, which did its damnedest to digest me. Luckily nothing it excreted was a me-solvent. So we have tree trunks, which are bones; and roots, which are stomachs, intestines, and livers, floating in a cloud above them. Two kilometers high and growing on an exceptionally cold and deep abyssal plain, across an area the size of Pennsylvania, and I think it might all be one big organism; definitely a lot of the tubes in the canopy hook to more than one trunk. Everyone will now please experience some real awe and surprise, okay?”

Lars’s expression was flat, drawn, almost angry. “You said you are worried and scared.”

“Two kilometer high bones with a curtain of guts floating above them sounds like plenty to worry about to me,” Stephanie said.

Lars turned his Shut up, you’re just a reporter glare on her — actually it wasn’t easy to tell it from shut up, you’re just my wife, Stephanie thought spitefully.

Nicole winked at her, startling her into silence more effectively than Lars’s glare. “Well,” Nicole said, “When I drilled cores, I found the outer walls are riddled with little tubes and pockets, and what’s in them is chopped Earth life. Seafood salad, you might call it, bugs and fish and seaweed and whales, all pretty much blenderized and packed in. That’s where some of the marine life went — ground up and stuffed it into those pockets in the bone. Incidentally, Stephanie, at a guess, the three vanished people from that capsized yacht very likely ended up in there, too, so you may want to watch how you break this news until someone talks to their families. Anyway, there’s roughly a twenty-meter-thick wall, according to the positron activation scan, that’s all that pocketed bone. Inside that, which I couldn’t drill to, and the positrons couldn’t penetrate to, the acoustic probes showed drastic changes of density, and NMR plus meson tomography eventually teased out what’s in the middle layer and the core.

“The middle layer is larger and smaller alternating chambers, all about seventy meters from the outer wall to the inner wall, laced with reinforcing struts of more bone. The larger chambers, which extend about eighty meters in the direction of the trunk, contain very high purity hydrogen peroxide, which is so unstable around biological material that there must be a special coating or something on the inner surfaces of those chambers to keep it from dissociating violently. Between hydrogen peroxide chambers, there are smaller forty-five-meter-long chambers filled with a mix of twenty percent toluene, seventy percent octane, and ten percent heptane — whoever said gasoline, that’s it. And the core is a two-meter-thick bone wall surrounding an empty —”

The intercom hooted the signal for an emergency announcement. “This is the captain. Bathygraphy room wants you all to know that the imaging is showing all those big structures are now floating upwards, pushing right up through that canopy. They all let loose at once, and they’re rising at about a meter and a half per second, so they’ll be breaking the surface here in about twenty minutes. We can’t run two hundred kilometers in the thirty minutes before they surface — all we can do is try to dodge the big towers as they float up and keep our intakes clear of all that canopy gunk. I know you’ll want to observe whatever’s happening; please be careful in moving around the ship and remember that we could have a sudden collision with one of those huge things. They seem to be staying upright as they rise, and if that continues there should be space between them.”

“They’ll be at the surface in twenty minutes?” Nicole said. “Come on, people, grab your parkas and come up and see this!”

Most of the scientists stood, but Lars gestured for them to sit. “We have work to do, don’t we? Alerting the rest of the planet, making sure they know what’s going on so that if we don’t make it they have our information? And perhaps deciding what we should do? Shouldn’t we —”

Nicole said, “I am useless for most of that, and if you want me, phone me. Specifications of what I found are on the big screen here.”

“And this is my chance to interview Nicole and record whatever comes up,” Stephanie said, and followed her out. Lars said nothing and didn’t look at either of them, intent on putting together his “response teams” and “brainstormers” and “issue teams,” but Stephanie saw by the set of his shoulders that he was as angry as he permitted himself to be in public.

Out on the deck, the sky was clear, and after Nicole spoke on her wristcom with the bridge, they turned off running lights; the sky was instantly powdered with stars, with hundreds of minute shooting stars crossing from northeast to southwest.

“The iron,” Stephanie said, staring up at it. “Lars is so terrified that that is what has caused this . . . um, this whatever this is.”

“Well, he might be right, but that’s not a reason for him to be upset, if I’m guessing right. The iron enrichment did what it was supposed to do and took an immense amount of carbon out of the atmosphere, and it fed a lot of people along the way. Nothing to be ashamed of for that.”

“What are you guessing?”

Nicole extended her hand. “Come on over here; it’s more exposed but we can see better. Let me lay out this thought. Before we towed asteroids into orbit around the earth, fastened robots onto them, and started shooting chunks of iron into the atmosphere above the Southern Ocean, what was the main reason why this area wasn’t producing much biomass?”

“Well, lack of iron, obviously.”

“And where did the little bit of iron there was come from?”

“Meteors. That was the argument for why it was safe to do this. Because the process was completely natural, and they were just ramping it up.”

“There you go. Now just watch and think about all these meteors for a while; see if I can lead you onto my guess. I’ve got a better grip than you, so let me hold you so you don’t have to worry about slipping off.”

Her strong arms gripped around Stephanie’s waist, holding her tight, and Nicole’s body shielded her from the wind, now coming from astern; she gazed up at the unending procession of shooting stars, streaking down into the atmosphere as the bombardment from the asteroid chunks continued. Some people wanted this shut down as soon as the strange growth started, but there was no proof that the iron was driving it, and the artificial meteor shower has been going on for decades, Stephanie thought. But that’s politics and policy, and Nicole doesn’t care about those things, so that isn’t what she’s trying to make me see.

What does she care about? I barely know her.

The horizon-to-horizon smear of stars was streaked everywhere with swift shooting stars. Nicole’s arms and body held her warm and safe on the freezing deck. The shooting stars plus the security turned her mind to thoughts of being a small girl, back when father had told her the forest might die from the heat and the dryness, back when she had watched the little screen and seen her father’s old friend, Lars, explaining what they would have to do, because there was no longer time for anything gradual . . .

That awakened other memories on the screen, of Lars standing with Nicole, the police arresting him, the trial scenes, the moment when he and Nicole came down the steps with arms raised in triumph . . .

She thought of the short videos, when she was in grade school, of the solar sail rigs dragging chunks of the iron asteroids, as big as airplane hangars, into Earth orbit, of the toy-truck-like pebblers, tunnelers, melters, and shooters crawling over surface of each chunk of iron like so many swarming termites, of the dozen barrels on each shooter spraying bits of iron, anything in size from a sesame seed to a tennis ball, out at a rate of dozens per minute . . . Lars’s voiceover explaining how a million little meteors a day could cool the Earth, bring back the rains, feed the fish to feed the people . . .

Of her graduating class trip, the first time she had been south of the equator, standing on the deck of the big tour ship and watching the iron come in to make the oceans bloom . . . just a couple of years, then, before she met Lars . . .

And Nicole had been here all that time, fresh back to Earth when the plan was announced, walking the seabed and swimming between the icebergs before the first artificial meteors fell . . .

Nicole had lived a whole lifetime before hers, and how was she to judge it or understand it? She knew only that she trusted the person holding her, and knew that humaniform and human, daughter of the far planets and daughter of Africa, at least shared wanting to know more than wanting to govern, and placed truth before rules.

She thought until she said, “You think this is a natural process. Those . . . um, gasoline trees grow whenever the ocean blooms for long enough.”

“That’s what I think,” Nicole agreed.

“What are they for?”

“Stephanie, evolution doesn’t have a purpose; they’re not for anything. The question is what they do.”

Stephanie let her back press backward slightly, turning and raising her shoulders for a more secure place in Nicole’s hold. She thought for an instant that the warmth on the back of her neck, between cap and collar, was Nicole’s breath, then realized she didn’t breathe; it was the radiated warmth from her face. “Do you know what they do?”

“I have one idea that’s pretty crazy,” Nicole said. “That’s why, while we’ve been standing here, I’ve been sending the captain my text about it, and that’s why I’m going to hold onto you till we go below.”

“You’re predicting something big?”

“These things rushing up toward the surface are about twenty times as big as the biggest redwood, back before the warming killed them. The safest thing, the almost-Lars-in-its-tepid-chicken-shitness thing, that I can possibly say is, ‘I’m predicting something big.’”

Stephanie said, “I probably shouldn’t laugh at him. He’s my husband.”

“Didn’t mean to put you in an awkward spot. I still love him, myself, and how many ex-wives can say that after a few decades? But he’s about safety and security, making the world more certain than it would be otherwise. It’s a necessary part of the ecology of life. But so is surprise and amazement and wonder. And considering he married me . . . and now he’s married to you . . . I think he knows that he needs some of that in his life, too.” Her grip tightened, pulling Stephanie closer. “Whatever is about to happen should happen in the next minute.”

The ship barely rocked; overhead, the flurry of meteors continued, dug from the asteroids, fired into the Earth, politically guaranteed forever by the International Fishing Association, as Stephanie had said once in an article. The stars twinkled, and the ocean’s surface all around them began to rise into dark pools. The ship’s jets fired and Clarke scooted two hundred meters at top speed, almost throwing them to the deck, her stern swinging round to stop her just as quickly with another blast of the jets. As they scrambled to their feet, the dark pools welled up, into swellings, springs, hills of water punching through the thick mat, geysers, immense towers of seawater reaching toward the stars above them.

Nicole’s hands found the hip-belt of Stephanie’s parka, and for one absurd second she thought her husband’s ex intended to pants her out here. She started to laugh, but the sound was lost in the boom of seawater rushing into the sky; she closed her mouth as water poured down over the deck, and opened her eyes on the site of immense black columns, far bigger than any skyscraper ever built, rising slowly out of the sea, all around, a forest or a downtown of these mighty pillars.

Nicole pulled Stephanie down to the icy deck and lay across her, pinning her on her back, yanking the hood of the parka around her ears and screaming “ . . .your hands over your ears!”

Stephanie’s mittens stretched the parka hood tight around her head as she forced them in, covering her ears. The icy sea water poured down around her but with Nicole’s chest sheltering her face, she could breathe. Nicole’s more-than-human arms cradled her tight. She had only a moment to think, Now, what?

The light was blinding, even through closed lids; the shock was worse, and then they were flying, floating, until the sea slammed into Stephanie’s back, and she felt the burning sensation. It was only then that she knew her clothes had been on fire and that she was singed, salt water stinging at burns where the terrible heat and light had blasted away her thick winter clothing and left a pathway to her skin.

Far under the deadly cold water, she wanted to scream, but Nicole fastened her mouth over Stephanie’s, worked some strange trick that opened both jaws, and released Stephanie’s breath before giving her a burst of air, unneeded in a fusion-driven humaniform, from Nicole’s lungs. Three more times as they rose to the surface, Nicole fed her mouth-to-mouth air; she shuddered with cold, her skull contracted and squeezed her brain terribly, the salt in her bare flesh stung fiercely, but she lived.

As the water broke around her and she drew a free breath, she felt Nicole grab, slide, push, and a moment later, Nicole’s body was pressed against hers inside the oversized parka. Nicole swam on her back, forcing Stephanie’s head up into the air, kicking with great force, steering and adjusting with Stephanie’s arms along for the ride; she could no more have stopped Nicole from moving the arms than she could have pushed back against a bulldozer.

Within the parka, the seawater became blood-warm; Nicole had cranked up her fusor and was heating the space inside the coat to keep Stephanie from hypothermia.

Stephanie shook her head to clear the hair from her face, and gasped, “Thank you.”

“Look up,” Nicole said, still stroking. “Look up, don’t miss this.”

Stephanie became aware that the black and green sea surface was lighted as if by a spotlight, brighter than day. She arched her back, pressing her belly hard against Nicole’s, and looked overhead, into the brilliant welding-arc white lights that filled the sky. She watched, numb with wonder, as the warm, delicate surface of Nicole’s skin brushed against her, warming her, rippling with the effort of moving them across the sea, supporting her. Stephanie gazed into the sky, and the brilliant lights grew dimmer and smaller as the distance increased. In a flurry of no more than five seconds, the bright lights all flared for an instant, then dimmed into a faint red glow that faded into the dark of the sky, where the stars were coming out again.

Nicole shouted “Clarke ahoy!” a few times before one crewman, still fighting a fire in the superstructure, heard her. A few minutes and some hard work with a winch, and they were hustled across the wreckage on the deck, and down into the intact, if scrambled, guts of the ship.

At the door to Stephanie’s and Lars’s cabin, Nicole said, “You’ll want to be there when I present in a few minutes.”

“Yeah.” Stephanie was shaking with the terror of the last few minutes. “Just . . . hey, thank you.”

“I’m glad there was one human witness, by naked eye, and it was you.” Nicole moved to kiss her cheek; Stephanie turned to take it on the mouth. Gently, Nicole turned Stephanie’s face away. “You’re still married. And this is a stress reaction. Now, take a shower, and I’ll have everyone together in the main conference room in a few minutes.”

The meeting was delayed while they stabilized broken bones on two scientists and treated Stephanie’s burns, but that gave Captain Pao time to establish that Clarke was “floating, functional, and able to take us home,” as she put it, in the opening remarks to the meeting. Besides the scientific and technical people, as many of the crew as did not have other duties were packed in to hear Nicole talk. The captain added, “When I took this job, I wondered why a science ship was armoured and equipped like a nukeproof International Patrol disarmer, but I promise I’ll never wonder again. We’ll limp, but we’ll limp clear to Cape Town. For the rest — Nicole?”

Nicole stood. “I think the first thing you’re entitled to know is the answer to what everyone shouted during the burst: What the hell was that? So here goes. I think we’ve just confirmed one of the main hypotheses about why Martian and Europan life are so similar to Earthly life. The answer is what I called the ‘upside-down trees,’ what Stephanie calls the ‘gasoline trees,’ and what I just heard Captain Pao call the ‘big rocket bush.’ I think it’s one path of panspermia — life spreading through space.

“The seed or spore of the gasoline tree arrived, perhaps, in a chunk of bone, tumbling through our air in a slow enough approach not to burn up or destroy the life it carried, sometime in the last half-billion years. It grew on the sea floor as slowly and coldly as stalactites on a cave ceiling. But now and then, a big meteor shower; or a cloud of interstellar dust; or the temporary capture of an asteroid inside Earth’s Roche limit; or the right volcanic eruption, or perhaps the right impact on the moon, caused iron to rain down for a few decades, creating an immense bloom in the Southern Ocean, or one of its ancestor oceans. Or, in this case, the human race, in an increasingly warm soup of its own brewing, decided to clear out centuries of excess carbon dioxide in the air with rapid growth of phytoplankton.

“When such a bloom persists long enough to fill the waters with life, the gasoline tree releases, or maybe synthesizes, the millions of species that make up the mat. The mat traps everything it can in that huge area of ocean, and drags it all to the centre, where some of the biomass is shredded and put in the bone cavities, and nearly all of it is oxidized for energy to fuel the construction of the bone towers, which are, just as Captain Pao said, rockets.

“Those rockets have just launched. A sampling of a few billion tons of Earthly life is on its way out beyond the solar system, to wherever it may come down; at a guess, the bone will crumble slowly into small pieces, each still pocketed with Earth life, and most of it will just continue through space forever, but some small fraction will rain down on many worlds as grains and bits, across perhaps as long as a billion years. On already-living worlds, Earth’s genetic material will introduce new possibilities; on worlds not yet alive, it will provide many possible bases for a start. In any case, what we have just witnessed is as natural as the swarming of bees, the blowing of cottonwood fluff, or the sudden hatching of shrimp in dry salt lakes after a rainstorm fills them — just on such a long cycle that spring, or the rain, doesn’t come very often. We may have similar events from time to time, here or elsewhere. Now —”

Lars asked, “And what must we do to prevent these eruptions?”

“What must we do to stop spring?” Nicole said. “Or continental drift? Or beaver pond succession? Lars, a natural process is a natural process; eventually we understand it and fit the way we live around it. Unless you want to go down in history with the people who controlled every forest fire, put levees on every river, and drained every estuary to create beachfronts. You remember how that worked out.”

Letting the autorec pick up the rest of the meeting, Stephanie edited her main story. Her file of possible follow-on ideas grew and burgeoned like . . . like the mat, she thought. Grab everything and throw it to the centre, wrap it up for others or use it for propellant.

She didn’t always understand Nicole’s conversations with the scientists, but she realized Nicole had at least established her explanation of the gasoline trees as the one to beat.

Meanwhile, Lars, who had looked sick and old at the start of the meeting, seemed to awaken and youthen by the minute. He reminded Stephanie of the way she’d first seen him, down on the floor playing with her and the other children, on the television explaining the plan to cool the planet, defying mobs of protesters during his marriage to Nicole — like the return of the hero she had committed her life to.

Except maybe committing my life to a hero isn’t what I want to do. Except it might be. Except . . .

The meeting wound down; on the way out, Nicole touched her shoulder, gently, and murmured, “As the more experienced wife-of-Lars, I want to suggest that you go straight to your cabin. He’ll be in there fretting.”

“Didn’t take much experience to know that. And thanks for everything.”

Back in the cabin, he was crying, big hard wracking sobs, and she was holding him before she had time to think what to do.

“I thought I’d lost you,” he said. “I thought I’d lost you. Then afterward there wasn’t a spare private second to tell you how glad I was you were alive.”

She held him close. “You must be upset, too, that every plan you’ve made and everything you’ve done to tame the planet is undone now. You have to start all over.”

He sank his pale fingers into her dark curls and guided her face close to his, as if afraid he’d lose sight of her. “Ten thousand interrelated things to put right, right away? Utter chaos where there needs to be order? What’s not to like? I’ve been bored out of my mind ever since the Rapid Sequestration Initiative turned out to work. But I was so afraid I’d lost you. I didn’t know what I could do with my life if you weren’t there.” He kissed her. “I’m declaring that there’s nothing to be done until the science team reports, giving them six months, and ordering them to use it all. You and I are going somewhere, somehow, to celebrate the start of another lifetime of chaos and challenge, the best work there is.” He kissed her again, slowly and tenderly, as if making sure he remembered. “So this might be our longest vacation for a decade to come. Where do you want to go? What do you want to do?”

“Surprise me,” she said.