A mile below the lowest cloud, rock breaches water and the sea begins.

It has been given many names. Each inlet and bay and stream has been classified as if it were discrete. But it is one thing, where borders are absurd. It fills the spaces between stones and sand, curling around coastlines and filling trenches between the continents.

At the edges of the world the salt water is cold enough to burn. Huge slabs of frozen sea mimic the land, and break and crash and reform, crisscrossed with tunnels, the homes of frost-crabs, philosophers with shells of living ice. In the southern shallows there are forests of pipe-worms and kelp and predatory corals. Sunfish move with idiot grace. Trilobites make nests in bones and dissolving iron.

The sea throngs.

There are free-floating top-dwellers that live and die in surf without ever seeing dirt beneath them. Complex ecosystems flourish in neritic pools and flatlands, sliding on organic scree to the edge of rock shelves and dropping into a zone below light.

There are ravines. Presences something between molluscs and deities squat patiently below eight miles of water. In the lightless cold a brutality of evolution obtains. Rude creatures emit slime and phosphorescence and move with flickerings of unclear limbs. The logic of their forms derives from nightmares.

There are bottomless shafts of water. There are places where the granite and muck base of the sea falls away in vertical tunnels that plumb miles, spilling into other planes, under pressure so great that the water flows sluggish and thick. It spurts through the pores of reality, seeping back in dangerous washes, leaving fissures through which displaced forces can emerge.

In the chill middle deeps, hydrothermic vents break through the rocks and spew clouds of superheated water. Intricate creatures bask in this ambient warmth their whole short lives, never straying beyond a few feet of warm, mineral-rich water into a cold which would kill them.

The landscape below the surface is one of mountains and canyons and forests, shifting dunes, ice caverns and graveyards. The water is dense with matter. Islands float impossibly in the deeps, caught on charmed tides. Some are the size of coffins, little slivers of flint and granite that refuse to sink. Others are gnarled rocks half a mile long, suspended thousands of feet down, moving on slow, arcane streams. There are communities on these unsinking lands: there are hidden kingdoms.

There is heroism and brute warfare on the ocean floor, unnoticed by land-dwellers. There are gods and catastrophes.

Intruding vessels pass between the sea and the air. Their shadows fleck the bottom where it is high enough for light to reach. The trading ships and cogs, the whaling boats pass over the rot of other craft. Sailors’ bodies fertilize the water. Scavenger fish feed on eyes and lips. There are jags in the coral architecture where masts and anchors have been reclaimed. Lost ships are mourned or forgotten, and the living floor of the sea takes them and hides them with barnacles, gives them as caves to morays and ratfish and cray outcastes; and other more savage things.

In the deepest places, where physical norms collapse under the crushing water, bodies still fall softly through the dark, days after their vessels have capsized.

They decay on their long journey down. Nothing will hit the black sand at the bottom of the world but algae-covered bones.

At the edges of the shelves of rock where cold, light water gives way to a creeping darkness, a he-cray scrambles. He sees prey, clicks and rattles deep in his throat while he slips the hood from his hunting squid and releases it.

It bolts from him, diving for the shoal of fat mackerel that boil and re-form like a cloud twenty feet above. Its foot-long tentacles open and whip closed again. The squid returns to its master, dragging a dying fish, and the school reknits behind it.

The cray slices the head and tail from the mackerel and slips the carcass into a net bag at his belt. The bloody head he gives his squid to gnaw.

The upper body of the cray, the soft, unarmored section, is sensitive to minute shifts of tide and temperature. He feels a prickling against his sallow skin as complex washes of water meet and interact. With an abrupt spasm the mackerel-cloud congeals and disappears over the crusted reef.

The cray raises his arm and calls his squid closer to him, soothes it gently. He fingers his harpoon.

He is standing on a granite ridge, where seaweed and ferns move against him, caressing his long underbelly. To his right, swells of porous stone rise above him. To the left the slope falls away fast into disphotic water. He can feel the chill emanating from below. He looks out into a steep gradation of blue. Way overhead, on the surface, there are ripples of light. Below him the rays peter swiftly out. He stands only a little way above the border of perpetual dark.

He treads carefully here, on the edge of the plateau. He often comes to hunt here, where prey are less careful, away from the lighter, warmer shallows. Sometimes big game rises curiously from the pitch, unused to his shrewd tactics and barbed spears. The cray shifts nervously in the current and stares out into the open sea. Sometimes it is not prey but predators that rise from the twilight zone.

Eddies of cold roll over him. Pebbles are dislodged around his feet and bounce slowly down the slope and out of sight. The cray braces himself on the slippery boulders.

Somewhere below him there is a soft percussion of rocks. A chill not carried by any current creeps across his skin. Stones are realigning, and a spill of thaumaturgic wash is spewing through new crevices.

Something baleful is emerging in the cold water, at the edge of the dark.

The cray hunter’s squid is beginning to panic, and when he releases it again, it jets instantly up the slope, toward the light. He peers back into the murk, looking for the source of the sound.

There is an ominous vibration. As he tries to see through water stained by dust and plankton, something moves. Way below, a plug of rock bigger than a man shudders. The cray bites his lip as the great irregular stone falls suddenly free and begins a grinding descent.

The thundering of its passage reverberates long after it has become invisible.

There is a pit in the slope now, that stains the sea with darkness. It is quiet and motionless for a time, and the cray fingers his spear with anxiety, clutching at it and hefting it and feeling himself tremble.

And then, softly, something colorless and cold slips from the hole.

It confuses the eye, flitting with a grotesque organic swiftness that seems to belie intention, like gore falling from a wound. The he-cray is quite still. His fear is intense.

Another shape emerges. Again he cannot make it out: it evades him; it is like a memory or an impression; it will not be specified. It is fast and corporeal and coldly terrifying.

There is another, and then more, until a constant quick stream dribbles from the darkness. The presences shift, not quite invisible, communing and dissipating, their movements opaque.

The he-cray is still. He can hear strange, whispering discourses on the tides.

His eyes widen as he glimpses massive backbent teeth, bodies pebbled with rucks. Sinuous muscled things fluttering in the freezing water.

The he-cray starts and steps backward, his feet skittering on sloping stone, trying to quiet himself but too slow-small shattered sounds emerging from him.

With a single motion, a lazy, predatory twitch, the dark things that huddle in council below him move. The he-cray sees the darks of a score of eyes, and he knows with a sick-making fear that they are watching.

And then with a monstrous grace, they rise, and are upon him.

Chapter Twelve

The next day was New Year’s Eve.

Not, of course, to the Armadans, for whom it was a day marked only by a sudden increase in warmth, making it merely autumnal. They could not ignore the fact that it was the solstice, the shortest day of the year: but they did not treat that as of much importance. Beyond a few cheerful remarks about the nights drawing in, the day went unremarked.

But Bellis was sure that, among the New Crobuzon press-ganged, she was not alone in keeping track of the days back home. She speculated that there would be subdued parties speckled across the ridings that night. Quiet, so as not to stand out, or to alert the yeomanry or the proctors, or whatever authority there was in a particular riding, that some among the cramped terraces and galleys of Armada were loyal to alternative calendars.

It was a kind of hypocrisy, she vaguely acknowledged: New Year’s Eve had never meant anything to her before.

For the Armadans, it was Horndi, the beginning of another nine-day week, and a day that Bellis had free. She met Silas on the bare deck of the Grand Easterly.

He took her to the star’d-aft edge of Garwater, to Croom Park. He had been surprised that she had not visited it before, and as they entered it and passed deep into its byways, she could understand why.

The bulk of the park was a long strip, more than a hundred feet wide and almost six hundred long, on the huge body of an ancient steamer whose nameplate had long been effaced by nature. The greenery spread across broad, swaying bridges to two old schooners lined up back-to-back, almost parallel to the great ship. Fore of the steamer, it extended onto a hunkered little sloop with long-dead guns, part of the fabric of Curhouse riding, sharing the park between the two boroughs.

Bellis and Silas wandered tangled pathways, passing the granite statue of Croom, the pirate hero from Armada’s past. Bellis was overwhelmed.

Unknown centuries before, the architects of Croom Park had set to covering the fabric of the war-shattered steamer with mulch and loam. Eddying on ocean currents, there was no ground for Armadans to till or fertilize and, like their books and money, they had had to steal it. Even that, even their earth, their mud, was plundered over years, dragged in great trenches from coastal farms and forests, torn from bewildered peasants’ plots and taken back across the waves to the city.

They had let the ruined steamer rust and rot, and had filled its holed carcass with the soil they had stolen, starting in the forepeak and engine rooms and the lowest coal bunkers (deposits of coke still unused, packed once again in seams below tons of dirt), piling the earth around the moldering propeller shaft. They filled some of the big furnaces and left others half empty, encased them, metal air bubbles in the striae of marl and chalk.

The landscapers moved up to decks of cabins and staterooms. Where walls and ceilings had escaped injury, they perforated them raggedly, rupturing the integrity of the little rooms and opening passageways for roots and moles and worms. Then they filled the scraps of space with earth.

The ship was low in the water, kept buoyant by judicious air pockets and by its tethering neighbors.

Above the water, in the open air, layers of peat and dirt spread out and reclaimed the main deck. The raised bridge, the aftercastle and observation decks and lounges, became steep knolls skinned in topsoil. Abrupt little hills, they burst in tight curves of earth from the surrounding plateau.

The unknown designers had performed similar transformations on the three smaller wooden boats close by. That had been much easier than working on iron.

And then there was the planting, and the parkland had bloomed.

There were copses of trees across the steamer’s body, old and densely spaced, tiny conspiratorial forests. Saplings, and many midsize trees a century or two old. But there were also some massive specimens, ancient and huge, that must have been uprooted full-grown from wooded shorelines and replanted scores of years ago, to grow old aboard. Grass was everywhere underfoot, and cow parsley and nettles. There were cultivated flowerbeds on the Curhouse gunboat, but on the steamer’s corpse the woods and meadows of Croom Park were wild.

Not all the plants were familiar to Bellis. In its slow journeys around Bas-Lag, Armada had visited places unknown to New Crobuzon’s scientists, and it had plundered those exotic ecosystems. On the smaller ships were little glades of head-high fungus, that shifted and hissed as walkers passed through them. There was a tower covered in vivid red, thorned creepers that stank like rotting roses. The long forecastle of the star’d-most ship was out of bounds, and Silas told Bellis that beyond the intricately woven fence of briars, the flora was dangerous: pitcher plants of odd and unquantified power, wake trees like predatory weeping willows.

But on the old steamer itself, the landscape and the foliage were more familiar. One of its raised deck-hills was paved inside with moss and turf and made into sunken gardens. Lit and kept alive by bright gaslight and what little day came through dirt-caked portholes, plants of different themes filled each of the cabins. There was a tiny tundra garden of rocks and purple scrub; a desert full of succulents; woodland flowers and meadowland-all adjoining, all linked by a dim corridor knee-high in grass. In its sepia light, under warpaint of verdigris and climbing plants, plaques pointing to the mess and the heads and boiler rooms could still be read. They were crossed by paths well-worn by woodlice and ladybirds.

A little way from its entrance-a door in the hill-out in the air, Bellis and Silas walked slowly in the damp shade.

They had visited each of the four ships of the park. There were only a few other people in the green environs with them. On the aft-most of the vessels Bellis had stopped, shocked, and pointed across the gardens and the reclaimed rails of the deck, out over a hundred feet of ocean to the city’s edge. Tethered there, she had seen the Terpsichoria. The chains and ropes that bound it were clean. New bridges connected it to the rest of the city. An architectural skeleton of wood loomed from its main deck: a building site, foundations.

This was how Armada grew for its populace, swallowing up prey and reconfiguring them, rendering them into its own material like mindless plankton.

Bellis felt nothing for the Terpsichoria, had only contempt for those who felt affection for boats. But seeing her last link to New Crobuzon brazenly and effortlessly assimilated depressed her.

The trees around them were evergreen and deciduous in an unruly mix. Silas and Bellis walked through pines and the black claws of leafless oaks and ash. Old masts soared over the canopy like the most ancient trees in the forest, barked in rust, dangling ragged foliage of long-frayed wire rigging. Bellis and Silas walked in their shadows, and in the shadows of the wood, past grassy undulations broken by little windows and doors, where cabins had been effaced by earth. Worms and burrowing animals moved behind the cracked glass.

The steamer’s ivy-caked chimneys disappeared behind them as they moved into the heart of the wood, out of sight of the surrounding ships. They traced spiraling paths that wound back on themselves arcanely, seeming to multiply the space of the park. Blistered cowls broke from the ground, choked with brambles; roots and vines entrapped the capstans and coiled intricately through the guardrails of moss-cushioned ladders leading into blank hillsides.

In the shade of a cargo derrick become some obscure skeleton, Bellis and Silas sat in the wintery landscape and drank wine. As Silas rummaged in his little bag for a corkscrew, Bellis saw his bulging notebook inside. She picked it up and looked at him questioningly, and when he nodded his permission she opened it.

There were lists of words: the jottings of someone trying to learn a foreign language.

“Most of that stuff’s from The Gengris,” he said.

She turned slowly through the pages of nouns and verbs, and came to a little section like a diary, with dated entries written in a shorthand code she could make little of, words pared down to two or three letters, punctuation dispensed with. She saw commodity prices, and scribbled descriptions of the grindylow themselves: unpleasant little pencil sketches of figures with prodigious eyes and teeth and obscure limbs, flat eel-tails. There were heliotypes attached to the pages, executed furtively, it seemed, in dim light; unclear sepia tints, discolored and water-stained, the monstrosity of the figures they depicted exaggerated by blisters and impurities in the paper.

There were hand-drawn maps of The Gengris, covered in arrows and annotations, and other maps of the surrounding water of the Cold Claw Sea, the topography of submerged hills and valleys and grindylow fortresses picked out in different colors for different rocks, granite and quartz and limestone, carefully corrected over several pages. There were suggestive sketches of machinery, of defensive engines.

Silas leaned over her as she read, pointing out features.

“That’s a gorge just south of the city,” he said, “that leads right up to the rocks separating off the sea. That tower there”-some irregular smudge-“was the skin library, and those were the salp vats.”

Beyond those pages were scrawled diagrams of gashes and tunnels and clawed machines, and mechanisms like locks and sluices.

“What are these?” she said, and Silas glanced over, and laughed when he saw what she was looking at.

“Oh, the embryos of big ideas-that sort of thing,” he said, and smiled at her.

They sat with their backs to an overgrown stump, or perhaps the earth-smothered anatomy of a binnacle. Bellis put Silas’ book away. Still not quite at ease, she leaned in and kissed him.

He responded gently, and an aggression came to her, and she pushed herself into him more firmly. She drew away for a moment, her face set, and looked at him staring back at her with pleasure and uncertainty. She tried to parse him, to understand the grammar of his actions and reactions, and she could not.

But frustrated as she was by that, she felt intimately how his antagonisms mirrored hers. His despite and hers-at Armada, at this absurd existence-had become conjoined. And it was an extraordinary relief and release to share even something as cold as that.

She held his face and kissed him hard. He responded eagerly. When his arm came slowly around her waist, and his fingers crooked and combed her hair, she broke from him and took hold of his hand. She pulled him after her, back through the winding ways of the park, portward, to her home.

In Bellis’ room, Silas watched silently as she undressed.

She draped her skirt, shirt, jacket, and bloomers over the back of her chair and stood stripped bare in the fading light of her window, letting down her scraped-up hair. Silas stirred. His clothes were scattered like seed. He smiled at her again, and she sighed and smiled too, finally, deprecatingly, for what seemed the first time in months. With that smile came an unexpected little stab of shyness, and with the smile it quickly left again.

They were not children; they were not new to this. They did not fumble or panic. She walked to him and straddled him with practiced grace and desire. And when she did, pushing against his cock, when he wrestled his hands out from where she had pinioned them, he knew how to move her.

Passionate; loveless but not joyless; expert; eager. It made her smile again, and gasp and come in a great gout of relief and pleasure. When she lay back in the narrow bed, having taught him how she liked to fuck and learned his own predilections, she glanced up at him (his eyes closed, sweating). She checked herself and verified that she was still lonely, still as numb to this place as ever. She would have been astounded to find it any other way.

But still, but still. Even so. She smiled again. She felt better.

For three days, Tanner lay in the surgery, strapped to the wooden table, feeling the tower and the ship move slowly and slightly beneath him.

Three days. He moved only inches at a time, wriggling against the restraints, shifting slightly to the left or right.

Most of the time he swam in glutinous aether dreams.

The chirurgeon was kindly, and kept him drugged as much as was possible without damaging him, so Tanner meandered in and out of twilight consciousness. He muttered to himself, and to the chirurgeon, who fed him and wiped him like a baby. He would sit with Tanner in his spare minutes or hours, and talk to him, pretending that his absurd and frightening responses made sense. Tanner spat out words or was silent, or wept and giggled: drugged; feverish; sluggish; cold; soundly sleeping.

Tanner had blanched when the chirurgeon had told him how it would have to be. To be shackled again, to be strapped down while his body was rebuilt. The narcotic- and agony-raddled memories of the punishment factory had assaulted him.

But the chirurgeon had gently explained that some of the procedures were fundamental; some would involve the reconfiguration of his insides from the tiniest building blocks up. He could not move while the atoms and particles of his blood and lungs and brain found their ways along new pathways and met in alternative combinations. He must be still and patient.

Tanner acquiesced, as he had known he would.

On the first day, as Tanner lay deep in chymical and thaumaturgic sleep, the chirurgeon opened him.

He scored deep gashes in the sides of Tanner’s neck, then lifted off the skin and outer tissue, gently wiping away the blood that coursed from the raw flesh. With the exposed flaps oozing, the chirurgeon turned his attention to Tanner’s mouth. He reached inside with a kind of iron chisel and slid it into the pulp of the throat, twisting as he pushed, carving tunnels in the flesh.

Constantly vigilant that Tanner was not choking on the blood that ran into his mouth and throat, the chirurgeon created new passageways in his body. Runnels linked the back of Tanner’s mouth to the openings in his neck. Where the new orifices opened behind and below his teeth, the chirurgeon ringed them with muscle, pushing it into place with a clayflesh hex, stimulating it with little crackles of elyctricity.

He stoked the fire that drove his bulky analytical engine, and fed it program cards, gathering data. Finally, he wheeled into place alongside the gurney a tank containing a sedated cod, and linked the motionless fish to Tanner’s body by a cryptic and unwieldy construction of valves, gutta-percha tubes, and wires.

Homeomorphic chymicals sluiced dilute in brine across the cod’s gills, and then through the ragged wounds that would be Tanner’s. Wires linked the two of them. The chirurgeon muttered hexes as he operated the juddering apparatus-he was rusty with bio-thaumaturgy, but methodical and careful-and kneaded Tanner’s bleeding neck. Water began to drool through the holes and over the opened-up skin.

For most of the night, the scene was replayed, the surgery swaying gently with the water below. The chirurgeon slept a little, periodically checking Tanner’s progress, and that of the slowly dying cod suspended in a matrix of thaumaturgic strands that dragged out its demise. He applied pressure when it was needed, changed the settings of finely calibrated gauges, added chymicals to the sluicing water.

In those hours, Tanner dreamed of choking (while he opened and closed his eyes, unknowing).

When the sun came up, the chirurgeon uncoupled Tanner and the fish from his machinery (the cod dying instantly, its body shrunken and wrinkled). He closed up the flaps of skin in Tanner’s neck, slimy with gelatinous gore. He smoothed them down, his fingers tingling with puissance as the gashes sealed.

Without Tanner waking-still drugged as he was, there was no danger of that-the chirurgeon placed a mask over Tanner’s mouth, sealed his nose with his fingers, and began to pump brine gently into him. For several seconds there was no reaction. Then Tanner coughed and gagged violently, spattering water. The chirurgeon stood poised, ready to release Tanner’s nose.

And then Tanner calmed. All without waking, his epiglottis flexed and his windpipe constricted, keeping the saltwater from entering his lungs. The chirurgeon smiled as water began to seep from Tanner’s new gills.

It came sluggishly at first, bringing with it blood and dirt and scab matter. And then the water ran clean and the gills began to flex, regulating it, and it pulsed across the floor in measured draughts.

Tanner Sack was breathing water.

He woke later, too vague to understand what had happened, but infected by the chirurgeon’s enthusiasm. His throat hurt terribly, so he slept again.

That was by far the hardest thing done.

The chirurgeon peeled back Tanner’s eyelids and bound to him clear nictitating membranes taken and modified from a caiman bred in one of the city’s farms. He injected Tanner with particulate life-forms that thrived in him harmlessly and interacted with his body, making his sweat a touch more oleaginous, to warm him and slide him through water. He grafted in a little ridge of muscle at the base of Tanner’s nostrils, and little nubs of cartilage, so that he could flex them closed.

Finally, the chirurgeon performed by far the easiest, if the most visible, alteration. Between Tanner’s fingers and his thumb, he stretched a membrane, a web of rubbery skin that he pinched into position, tethering it in Tanner’s epidermis. He removed Tanner’s toes and replaced them with the fingers from a cadaver, sewing and sealing them onto Tanner’s foot until he looked simian; then he changed the resemblance from ape to frog as he stretched more webbing between those once-more living digits.

He bathed Tanner, washed him in seawater. Kept him clean and cool, and watched his tentacles writhe in his sleep.

And on the fourth day Tanner woke, properly and completely. Untied, free to move, his mind empty of chymicals.

He sat up, slowly.

His body hurt; it raged in fact. It assaulted him in waves that beat with his heart. His neck, his feet, his eyes, dammit. He saw his new toes and looked away for a moment, a memory of the old horror of the punishment factory come back for a second, till he battened it down and looked again (More pus, he thought, with a shade of humor).

He clenched his new hands. He blinked slowly and saw something translucent slip across his vision before his eyelid came down. He breathed deep into water-bruised lungs and coughed, and it hurt, as the chirurgeon had warned it would.

Tanner, despite the pain and the weakness and the hunger and nervousness, began to smile.

The chirurgeon came in as Tanner grinned and grinned, and grunted to himself, and rubbed himself gently.

“Mr. Sack,” he said, and Tanner turned to him and held out his shaking arms as if to grab him, trying to shake his hand. Tanner’s tentacles flexed as well, trying to reach out in echo through the too-thin air. The chirurgeon smiled.

“Congratulations, Mr. Sack,” he said. “The procedures were successful. You are now amphibian.”

And at that-they couldn’t help themselves and didn’t try-both he and Tanner Sack laughed uproariously, even though it hurt Tanner’s chest, and even though the chirurgeon wasn’t certain what was funny.

When he got home, after hauling himself gingerly through the valleys of Booktown and Garwater, he found Shekel waiting in rooms that had never been so clean.

“Ah now, lad,” he said, shy of him. “That’s great what you’ve done, ain’t it?”

Shekel tried to grab him in welcome, but Tanner was too sore and held him back good-naturedly. They talked quietly into the evening. Tanner asked carefully after Angevine. Shekel told Tanner that his reading was improving, and that nothing much had happened, but that it was warmer now, could Tanner feel it?

He could. They crawled south at an almost geologically slow pace, but the tugs and steamers had been dragging them continuously for two weeks now. They were perhaps five hundred miles south of where they had been-they had traveled so far, with a motion so slow it was unnoticed-and the winter was waning as they approached the band of temperate sea and air.

Tanner showed Shekel the additions, the changes to his body, and Shekel winced at their oddness and inflammations, but was fascinated. Tanner told him all the things the chirurgeon had explained.

“You’ll be tender, Mr. Sack,” he had said. “And even when you’re well, I want to warn you: some of the cuts I’ve made, some of the wounds, they may heal hard. They might scar. In that case, I want you not to be downhearted or disappointed. Scars are not injuries, Tanner Sack. A scar is a healing. After injury, a scar is what makes you whole.”

“A fortnight, lad,” Tanner said, “before I’m back at work, he reckons. If I practice and all.”

But Tanner had an advantage the doctor had not considered: he had never learned to swim. He did not have to adjust a flailing, inefficient, slapping paddle into the sinuous motion of a sea dweller.

He sat by the dockside while his workmates greeted him. They were surprised, solicitous, and friendly. Bastard John the dolphin broke surface nearby, glaring at Tanner with his liquid, piggy eyes and emitting what were doubtless insults in his imbecilic cetacean chittering. But Tanner was not cowed that morning. He received his colleagues like a king, thanking them for their concern.

At the border of Garwater and Jhour ridings, there was a space in the fabric of the city, between vessels: a patch of sea that might have housed a modest ship formed a swimming area. Only a very few of the Armadan pirates could swim, and in such temperatures, few would try. There were only a handful of humans swimming in that patch of open sea, brave or masochistic.

Under the water, slowly, nervous of his new buoyancy and freedom, over hours that day and the next and next, Tanner spread his arms and hands, opening out the webs of skin and capturing the water, pushing himself forward in inexpert bursts. He kicked out in something like a breaststroke, those still-sore toes flexing, painful and powerful. The little presences he could not see or feel beneath his skin pulsed infinitesimal glands and lubricated his sweat.

He opened his eyes and learned to close only his inner eyelids-an extraordinary sensation. He learned to see in the water, unconstrained by any unwieldy helmet, any iron and brass and glass. Not peering through a porthole, but looking out freely, peripheral vision and all.

Slowest and most frightening of all, alone-who could possibly teach him?-Tanner learned to breathe.

The first inrush of water into his mouth closed his windpipe reflexively, and his tongue clamped back and his throat tightened and blocked the route to his stomach, and the seawater scored its way through his tender new pathways, opening him up. He tasted salt so totally it became quickly insensible. He felt rills of water pass through him, through his neck, his gills, and Godspit and shit and all he thought, because he felt no need to breathe.

He had filled his lungs before descending, out of habit, but aerated he was too buoyant. Slowly, in a kind of luxuriant panic, he exhaled through his nose and let his air disappear above him.

And felt nothing. No dizziness or pain or fear. Oxygen still reached his blood, and his heart kept pumping.

Above him, the pasty little bodies of his fellow citizens floundered across the surface of the water, tethered to the air they breathed. Tanner spun beneath them, clumsy still but learning, corkscrewing, looking above and below-up into the light and bodies and the massive sprawling interlocking shape of the city, down into the boundless blue dark.