The Air Garden Keeper

• Chapter 1 The Canopy of Leaves
• Chapter 2 First Signs of Wilt
• Chapter 3 The Hum of the Scrubbers
• Chapter 4 Sickly Sweet Spores
• Chapter 5 Sector Seven Drops
• Chapter 6 Phantom in the Vents
• Chapter 7 Unbalanced Chemistry
• Chapter 8 Whispers in Hydroponics
• Chapter 9 Blackened Roots
• Chapter 10 The Midnight Valve
• Chapter 11 Thinning Air
• Chapter 12 A Missing Keycard
• Chapter 13 The Moss Vaults
• Chapter 14 Footprints in the Soil
• Chapter 15 Static on the Comms
• Chapter 16 The Poisoner's Pattern
• Chapter 17 Choking Alarms
• Chapter 18 Grafting Hope
• Chapter 19 Cornered in the Bio-Ducts
• Chapter 20 Masks and Motives
• Chapter 21 The Saboteur Unmasked
• Chapter 22 Desperate Germination
• Chapter 23 Race for the Regulators
• Chapter 24 The Hull Garden
• Chapter 25 First Deep Breath
• Chapter 26 Blooms in the Dark

The rule on the Vanguard was simple enough for even a toddler in the crèche to recite: you don’t pull a green leaf unless you’re ready to explain it to three different committees.

Phoebe Mercer was twelve years old, which meant she had outgrown the crèche by four years, but she still checked over both shoulders before she reached into the canopy. Her boots were wedged into the titanium trellis that lined Ring Four’s inner spine, forty meters above the main deck. Below her, the central walkway looked like a ribbon of pale composite, crowded with morning shufflers heading toward the synthesis kitchens or the recycler bays. Up here, though, it was just humidity, the heavy scent of crushed fern, and the persistent green hum of life trying very hard not to die in an iron bottle.

"You’re lingering, Phoebe," came the voice through her earpiece. It was low, scratchy, and had the dry, rattling cadence of an old intake valve.

"I’m not lingering, Uncle Jesse. I’m assessing."

"You’re dawdling. Dawdling is what twelve-year-olds do when they’re hoping someone else will clean the algae traps in Bay Nine."

Phoebe sighed, letting the warm air fill her lungs before venting it through her nose. The air up here was the best on the ship—crisp at the front of the intake ducts, heavy with fresh oxygen that hadn't yet been cycled through two thousand pairs of lungs, six thousand livestock brooders, and the endlessly complaining scrubbers down in the keel. It smelled of wet earth and resin, two things that simply did not exist anywhere else within three light-years.

"The broadleaf philodendrons on row twelve have scale insects," she said, squinting through a battery-powered loupe at the underside of a glossy green plate the size of a dinner platter. "Just a few. Nothing catastrophic yet. But if they jump to the high-yield moss arrays, Jesse, we’ll be eating nutrient paste with an extra dose of chitin next month."

"Then dab them with mineral oil and move along," Jesse replied. "The morning cycle report is due at zero-eight-hundred. Director Vance is already pacing his office. I can hear his shoe leather through the deck plates."

"Director Vance paces because he drinks synthesized chicory instead of sleeping," Phoebe muttered.

She reached into her tool harness, an oversized rig of heavy webbing that had belonged to her mother. It was cinched as tight as the buckles would go, the stiff canvas smelling faintly of pine pitch and old copper. She pulled a glass vial of refined oil from its elastic sleeve, uncorked it with her teeth, and dabbed the tip of a natural-bristle brush into the amber fluid. With two swift, practiced strokes, she coated the clusters of tiny brown bumps on the leaf's central vein. The scale insects would suffocate quietly, without the need for aerosol pesticides that might make the deck officers sneeze or, worse, upset the delicate bacterial balance in the lower greywater basins.

The Vanguard didn’t tolerate imbalances. That was the first lesson her mother had taught her, back when Phoebe was barely tall enough to reach the drainage gutters. Balance was everything. If the oxygen creeped past twenty-one point eight percent, your eyes stung, the machinery ran hot, and every static spark from a wool jumper was an existential crisis. If it dropped below eighteen point five, people got headaches, grew stupid, forgot to seal hatchways, and drifted into hypoxic slumbers from which they didn't wake up.

Phoebe pocketed the oil, recorked it, and pulled herself hand-over-hand along the guide cable.

The Canopy of Ring Four was five kilometers of curving, tiered greenery suspended from the ceiling of the primary habitat drum. It wasn’t a park, though sometimes people who lived down in the windowless crew blocks called it that when they came up for their mandated twenty minutes of sun-simulation. It was a machine. A machine made of cellulose, chlorophyll, and trillions of microscopic stomata that inhaled what the humans exhaled and spat back what the humans needed to live. The mechanical scrubbers in the lower spine handled the heavy lifting—the bulk carbon dioxide extraction—but the scrubbers were crude, loud, and prone to blowing their gaskets. The canopy was the fine-tuner. It gave the ship its breath, its smell, and its sanity.

She swung down from the trellis onto the elevated catwalk, her rubber-soled boots landing with a dull thunk on the perforated grating. Beneath her feet, the nutrient channels gurgled happily. Water, enriched with nitrates filtered from the waste reclamation plants, rushed through transparent PVC pipes toward the root blocks.

"How are the runners on the sky-squash?" Jesse asked.

"Thick as my wrist," Phoebe said, walking down the central aisle between two towering hedges of engineered bamboo. The bamboo wasn’t for eating; its dense fibrous stems were harvested every nine months to be pulped for paper, cloth, and structural insulation. "We’ll need to prune them back from the high-voltage conduits by Thursday. If they bridge the insulator caps again, the lighting sector is going to short out."

"Put it on the docket. And Phoebe?"

"Yes?"

"Don't touch the ferns in Sector Three. Vance had a team down there yesterday taking core samples for the biometrics audit. If they find your thumbprints on their precious specimen slips, they'll write us up for interference."

Phoebe rolled her eyes, though Jesse couldn't see it. Jesse was stationed down in the central hub’s control shack, surrounded by thirty monitors that displayed everything from leaf-surface temperature to ambient nitrogen saturation. He was seventy-one years old, had lived his entire life between the hull plates, and walked with a hitch in his hip that he claimed came from falling out of a pecan tree during the ship’s second transition phase forty years ago. Phoebe knew for a fact the Vanguard didn't have pecan trees—they took up too much lateral space and their yield-to-mass ratio was terrible—but she never challenged him on it. People on the Vanguard held onto their stories the way they held onto fresh water rations.

"Sector Three is part of our circuit," Phoebe said. "The auditors don't know the difference between a Boston fern and a brake fern. Last time they did an audit, they tried to catalog the plastic hose couplings as invasive root stock."

"Just check the irrigation heads and leave the brass to do their tallying," Jesse said, though she could hear the grin in his gravelly voice. "Some of those junior clerks haven't seen an unharvested potato since their academy rotations. Be gentle with them."

Phoebe walked past the bamboo grove and emerged into the wide open sweep of the mid-canopy junction. Here, the artificial lighting tubes were mounted along the high arches of the ship’s structural ribs, blasting a crisp, six-thousand-Kelvin white that felt almost hot against her bare forearms. Her uniform was simple: dark green overalls, rolled up at the cuffs, and a gray undershirt that had been washed so many times the ship's emblem on the chest—a stylized star wrapped in an olive branch—had faded to a ghostly gray ring.

She loved this spot. If she leaned over the safety railing, she could see the curve of the habitat drum curling upward in front of her and behind her. Because the drum rotated at two revolutions per minute to generate three-quarters of Earth’s gravity, the horizon didn't drop away; it climbed. She looked up and saw buildings, streets, and small squares of artificial parkland hanging suspended above her head, inverted and bathed in the same pale glow. It never made her dizzy. To Phoebe, the universe had always been a curved pipe. The idea of an open world—one where the ground stayed flat until it met an infinite emptiness called the sky—sounded drafty, inefficient, and terrifyingly insecure.

She pulled a handheld sensor wand from her belt, clicking the trigger to wake the display. The screen blinked green:

O2: 20.9% | CO2: 410 ppm | HUM: 64% | TEMP: 22.1 C

Everything was pristine. The numbers had been like this since before she was born. Her mother had maintained these exact figures, recording them in neat, cursive script in the old cloth-bound ledger that sat on the corner of Jesse’s desk, long after the rest of the ship had switched to digital tablets. Phoebe had inherited the ledger, the tool belt, and the duty. There were other apprentices on the ship—boys learning to weld titanium plating in the dry docks, girls learning to synthesize amino acids in the chemical labs—but only one Keeper apprentice for Ring Four. Plants didn't respond well to shifts in personnel. They liked consistency. They liked knowing the exact pressure of the hand that checked their stems and the exact rhythm of the boots that passed their roots each morning.

She moved toward Sector Three, the transition marked by a shift from the thick, woody smell of the bamboo to the sharp, peppery scent of nasturtiums. The nasturtiums were planted along the margins of the raised beds to deter aphids and provide edible flowers for the senior staff’s dining room. Phoebe plucked a bright orange blossom, inspected it for thrips, and popped it into her mouth. It tasted like radishes and well water, crisp and sharp.

As she entered the fern vaults of Sector Three, the ambient sound changed. The loud hum of the main axial fans was muffled here, replaced by the persistent, rhythmic drip-drip-chink of the condensation recovery system. Hundreds of overhead copper pipes caught the sweat of the forest and funneled it down toward the secondary collection pans.

Then she smelled something that didn't belong.

It wasn't a bad smell, not at first. It certainly wasn't the sulfurous tang of an electrical burn or the sour, yeasty reek of a greywater leak. It was faintly sweet, like an overripe pear left too long in a warm locker, with a thin undercurrent of dry cardboard.

Phoebe paused on the grating, lifting her chin to test the air. The draft was coming from the portside intake riser, Vent 3-Alpha.

"Jesse," she said, touching her earpiece.

"Still here, Phoebe. Did you find Vance’s auditors? Tell them the green side goes up."

"Jesse, are they running a cleaning cycle on the scrubber banks for Ring Four?"

There was a rustle of papers on the other end, followed by the clatter of a keyboard with sticky keys. Jesse still refused to use the neural interface terminals, claiming they gave him dreams about maintenance schedules that ruined his sleep.

"Scrubber cycle isn't scheduled until twenty-one hundred hours," Jesse said. "They’re running on low bypass right now. Why? Did someone dump cooking fat down the drains again?"

"No," Phoebe said, walking slowly toward the wall of Vent 3-Alpha. "The air is sweet."

"Sweet is better than sour on a generation ship, girl."

"It’s not garden sweet," she said, her voice dropping. "It’s... chemical. Like almond extract, but sharper."

She stopped in front of the vent intake. It was a massive iron grille, three meters tall and two meters wide, set directly into the curved exterior hull wall. The heavy mesh was designed to keep stray leaves and runaway garden implements from being sucked into the high-velocity return shafts that fed the lower engine decks. Normally, the pull of air against the grille was strong enough to pin a work glove to the steel.

Today, the draw felt sluggish.

Phoebe held up her sensor wand to the metal slats. The numbers flickered, then stabilized:

O2: 20.7% | CO2: 440 ppm | HUM: 59% | TEMP: 23.4 C

The oxygen was slightly down, the carbon dioxide slightly up. Nothing that would trigger an alarm on the main bridge; systems fluctuated by tenths of a percent all the time, depending on how many people were exercising in the Ring Three gymnasiums or whether the light banks were at full intensity. But the humidity was five points lower than it had been fifty meters back, and the temperature was creeping up.

"Jesse, Vent 3-Alpha's draw is down fifteen percent."

"Probably just lint on the pre-filters," Jesse said, though his tone had lost its teasing edge. "The maintenance kids from Sector Two are supposed to vacuum those grates twice a week, but they’d rather spend their shift playing zero-gee handball in the ballast tanks."

"It’s not lint," Phoebe said.

She knelt on the damp grating. At the base of the intake grille, tucked behind the bushy fronds of a mature leatherleaf fern, sat a small access panel. The panel was secured by four hex-bolts and was marked with an embossed yellow triangle: ATMOSPHERIC CIRCULATION - AUTHORIZED CREW ONLY.

One of the hex-bolts was missing. The other three were finger-tight, their gray industrial paint scratched away around the edges to reveal bright, fresh silver underneath.

Phoebe touched the metal. It was warm. Machinery on the ship was usually lukewarm or freezing, depending on whether it was near a coolant line or an exterior hull bulkhead, but this warmth had a greasy, unnatural feel to it.

"Jesse," she said softly.

"Phoebe, don't go poking around in the ducts. If you drop a wrench down the main riser, it'll rattle around all the way to the propulsion block and they'll have my hide for rugs."

"Someone's opened the riser access," she said. She pulled a miniature multi-wrench from her harness and set the jaw against the nearest bolt. It turned without any resistance. "The paint is fresh-scratched. It was done this morning."

"Might have been the inspection crew," Jesse said, though he didn't sound entirely convinced. "Vance said they were checking the air-flow tolerances for the quarterly report."

"Inspectors use standard-issue security seals," Phoebe said. She pointed her flashlight into the seam where the panel met the frame. "The lead tag has been cut through with wire snips. Clean cut. Not logged."

She pulled the third bolt, then the fourth, and eased the square iron panel away from the wall. A blast of dry, warm air hit her face, carrying that strange, almond-and-cardboard scent much stronger now. It made the back of her throat tickle, a tiny, scratchy cough catching in her chest.

Behind the panel lay the dark, rectangular throat of the riser. The duct was lined with sound-dampening acoustic foam that felt dry and brittle under her fingers. It stretched back into the darkness, angling downward toward the deck plates of the lower machinery levels.

Phoebe unhooked her inspection lantern, sliding the toggle to narrow the beam into a tight white spear.

The light cut through the gloom of the duct. Five meters inside, where the shaft made a hard ninety-degree turn toward the keel, something was wedged into the acoustic baffles. It wasn't a tool, and it wasn't a standard filter cartridge. It looked like an iron cylinder, roughly the size of a fire extinguisher, strapped to the internal structural ribs with thick industrial zip-ties. A thin, flexible transparent tube ran from the cylinder’s brass regulator valve, drilled directly through the sheet metal of the duct wall, disappearing into the dark voids behind the garden's main irrigation conduits.

From the tip of the regulator, a tiny, rhythmic mist was puffing into the airstream.

Pffft. Pffft. Pffft.

Every four seconds, a cloud of micro-fine droplets vanished into the current, swallowed up by the thousands of cubic meters of air that were being drawn down into the ship’s primary respiratory loop.

"Jesse," Phoebe whispered, her fingers tightening on the edge of the open access hatch until her knuckles turned the color of chalk.

"Phoebe? What is it? You've gone quiet. I don't like it when you go quiet."

"There's something in the riser," she said. Her voice was steady, but her mouth felt suddenly dry, as if she had swallowed a handful of lime dust. "It’s not maintenance gear. It’s plumbed into the line."

On the cylinder’s gray-painted shoulder, half-obscured by the zip-ties, a small, stenciled label caught the lantern’s beam. It wasn't an agricultural symbol. It wasn't the green leaf of the Keeper’s Guild, or the blue gear of Engineering, or even the red cross of Medical.

It was a black serial number, stamped over a warning stripe that had been crudely painted out with shipboard primer.

Above her, in the great green sweep of the canopy, a drop of condensation fell from a high philodendron leaf, striking her forehead like an icy finger. Phoebe didn't wipe it away. She just stared at the little brass valve, watching the tiny white puffs merge silently into the breath of the ship.

The hiss of the regulator was so soft it sounded like an insect rubbing its wings behind the bulkhead.

Pffft. Pffft.

Phoebe kept her light fixed on the brass nozzle. The spray was practically invisible unless the beam hit it sideways, catching the prism of suspended moisture before the return draft tore it apart. It looked like breath on a frosty window, disappearing into nothingness.

"Phoebe?" Jesse’s voice rattled against her eardrum, sharp enough to make her flinch. "I asked what you’re looking at. If it’s an auxiliary booster pump from the coolant line, don't monkey with it. The plumbers have been bypassing the heat exchangers all morning because of a clog in Sector Five."

"It’s not a coolant pump," she said, keeping her voice low. She didn't know why she was whispering; the only things around were four thousand ferns and the indifferent rumble of the air ducts. But the ductwork acted like an acoustic horn. If you spoke into a secondary intake with enough volume, an engineer two decks down would swear someone was whispering inside his skull. "It’s a canister. Fastened to the frame with three-hundred-pound nylon ties. Jesse, it’s dosing the return air directly."

There was a silence on the comms line so thick that Phoebe could hear the faint, three-beat syncopation of the main drive humming through Jesse’s desk microphone. Down in the control shack, the old man was probably reaching for his reading spectacles, squinting at the status boards, trying to find an explanation that fit inside standard operating procedures. The Vanguard ran on manuals. If something wasn't listed in the blue-bound emergency binders or the yellow preventative maintenance schedules, it usually meant someone had made a paperwork error.

"Dosing it with what?" Jesse asked slowly.

"Smells like bitter almonds. And dry paper. It’s got a stencil on the side, under some grey primer. Looks like... CHEM-SPEC-9... then the rest is scratched out. Jesse, what’s Chem-Spec?"

"Chemical Specialties. Old stock. Hull-sealant thinners, heavy-duty cleaning alcohol, pipe descalers. Stuff from the initial outfitting that sits in the deep vaults behind the water reclamation plant. Half of it hasn't been uncorked since my grandfather had all his teeth." A pause, punctuated by the clack-clack of his mechanical keyboard. "There’s no requisition for toxic solvent dispersal in an active habit zone. That’s a Class One violation. That’s 'wake the Captain up before breakfast' territory."

"Should I cut the line?" She drew her wire shears from the outer thigh pocket of her overalls. The steel was cool, the rubber grips sticky from years of plant sap.

"Don't touch it," Jesse barked, his voice suddenly hard and clear. "You don't know the line pressure. If you snip a pressurized feed, you'll take a face full of whatever's in that iron pig. Back out of the hatch. Put the panel back on, finger-tight. Don't touch the lead seal."

Phoebe hesitated. She could reach the zip-ties with her arm extended. Two snips, a quick heave, and the entire assembly would come loose. But Jesse was right about the pressure. In training, they had drilled it into every apprentice: a pinhole leak in a high-pressure line could cut through flesh like a wire cheese-slicer.

"I’m coming down to the shack," she said.

"No. Finish the circuit through Sector Three. Check the leaves. If that stuff is venting into the return line, it’s being pulled down to the scrubbers first, but the backdraft might have drifted into the perimeter beds. Look at the margins. Tell me what the plants are doing."

She hated leaving the canister there, pulsing away in the dark throat of the ventilation riser, but she backed her shoulders out of the square opening. The metal edge caught the shoulder of her canvas harness with a dry rasp. She eased the square hatch back into place, sliding the four loose bolts into their housings, turning them just enough to bite the threads. From the outside, you couldn't tell the difference, except for the missing lead inspection disk that had once dangled from the upper-right corner like an ear tag on a prize heifer.

She stood, dusting off her knees. The knees of her overalls were permanently stained a dark, mossy green, a hue that three generations of laundry compound had failed to lift.

Sector Three was supposed to be the easiest leg of her morning walk. It was the fern vault—mostly low-maintenance varieties engineered for high surface area and minimal water uptake. The beds were tiered on broad, shallow shelves made of recycled composite foam, terraced like rice paddies along the curve of the outer hull. The path between them was barely eighteen inches wide, a catwalk of galvanized steel mesh that hummed faintly as the ship’s primary structural rings flexed under the centrifugal drag.

Phoebe walked with her fingertips trailing along the fronds of the Boston ferns.

Usually, the plants had a spring to them. A healthy Boston fern on the Vanguard was like an over-wound clock spring; you brushed it aside, and it snapped right back, spraying a tiny mist of gathered moisture against your forearm.

Today, they felt soft.

She stopped at Bed 3-Charlie, three meters downstream from the intake vent. The fronds here were broad, their edges delicately fringed like green lace. She lifted one. The tip didn't bounce. It stayed draped over her index finger, limp as wet silk.

"Jesse," she said into her mic, not waiting for him to prompt her. "The margin on the Boston ferns. They’re weeping."

"Weeping? You mean guttation? The humidity is down, Phoebe. Plants don't guttate when the air is dry; they close their pores to save water."

"I know what guttation looks like," she snapped, feeling a prickle of irritation. "This isn't clean water beads on the leaf edges. It’s... oily. It’s leaking from the sub-cellular margins. Like the cell walls are turning to jelly."

She took her loupe from her belt and bent double, resting her chin nearly on the edge of the composite trough. Under the six-times magnification, the leaf surface looked like a field of hexagonal tiles. Usually, the tiny green sausages of the guard cells were plump, holding the stomata open to breathe in the drum's carbon dioxide.

These weren't plump. They looked deflated, their borders blurred and weeping a pale, straw-colored liquid that gathered in the depressions between the leaf veins. As she watched, a tiny patch of green turned a dull, bruised slate-grey.

"Cell lysis," she whispered.

"Speak up, Phoebe. The fan in the primary rack is screaming again. Sounds like a bearing’s gone soft."

"The cell walls are breaking down, Jesse. It’s not just a drop in pressure. The leaves are melting from the inside out."

She moved down the path, her boots quickening their pace, the grating ringing under her weight. Bed 3-Delta: sword ferns. Their stiff, upright spears had begun to droop at the third node, nodding toward the drainage troughs like tired soldiers. Bed 3-Echo: the high-efficiency moss plates that lined the lower gutters. The moss was supposed to be a brilliant, vibrant emerald, so dense you couldn't push a fingernail through the mat to the plastic mesh beneath.

The top layer of the moss was turning the color of dried tea.

It was happening fast. Too fast for a biological blight. Fungal rots took days to show their threads; bacterial wilts crept along the vascular bundles over the course of three or four lighting shifts. This was chemical. It was like someone had taken a bucket of industrial stripper and misted it across the sector with an aerosol gun.

"How wide is it?" Jesse asked. His voice didn't have any banter left in it. It was flat, functional, and very cold. That was Jesse’s disaster voice. She had heard it only once before, when an ammonia line had ruptured in the cooling loops behind the synthesis floor two years ago.

"About twenty meters along the port rib," Phoebe said, swinging her lantern down into the drainage channel below the moss beds.

The water in the trough was supposed to be crystal clear, polished by the bio-filters before being returned to the primary reservoirs. Now, a thin, iridescent film floated on top of the current, swirling into oily crescents where the water dropped over the baffle plates.

"The runoff is contaminated," she said. "If this gets into the return manifold, it’s going straight to the secondary algae lagoons in Ring Five."

"No," Jesse said instantly. "The algae lagoons have automated shutoffs on the influx valves. If the pH drops past six-point-four, the gates drop."

"What if the pH doesn't drop?" Phoebe pulled a strip of test paper from the pocket of her harness and dipped the end into the oily film. The paper didn't turn red for acid or blue for base. It turned a strange, muddy purple, then the fibers of the paper themselves dissolved, leaving her holding a soggy wet tab of yellow cardboard. "Jesse, it’s not an acid. It’s an organic solvent. The sensors in the manifold aren't calibrated for synthetic organics; they’re looking for nitrates, phosphates, and heavy metals."

"Get down here," Jesse said. "Now. Don't touch the leaves with your bare skin, Phoebe. If your gloves have that slime on them, drop them in a disposal bin before you cycle through the airlock."

"I need to close the manual sluice on Bed Three," she said, looking down the long row of drooping greenery. "If I don't drop the brass gate, twenty tons of greywater will dump into the hub before you can get an override code from Vance."

"Phoebe—"

"It takes three seconds, Jesse. I’m right by the wheel."

She didn't wait for his reply. She scrambled three meters down the access ladder at the end of the catwalk, her boots sliding slightly on the wet composite rungs. The manual sluice wheel was mounted on the main drain manifold, a heavy iron ring painted fire-engine red, though the pigment had chipped away to reveal the dull grey zinc primer underneath. It was stiff; these gates were only turned during the annual system flush or when someone dropped an iron file into the gutters.

She set her boots against the frame, grabbed the spokes with her leather-palmed work gloves, and threw her weight backward.

The wheel groaned, the brass threads screeching against the collar as forty years of dried mineral deposits surrendered all at once. She spun it twice, three times, hearing the heavy bronze gate inside the pipe slide down through its track with a dull, wet clack. The sound of rushing water died instantly, replaced by the angry gurgle of the backup pooling against the seal.

The smell came up with the splash.

It hit her like a wet towel across the nose and mouth. Up close, the almond odor wasn't just sweet; it was thick, almost oily, coating the inside of her nostrils with a sensation like cold grease. Her lungs hitched, a violent spasm that doubled her over against the wheel. She coughed, her chest burning as if she had inhaled smoke from an electrical fire, though the air looked perfectly clear in the harsh white light of the overhead LED tubes.

She pressed her sleeve against her face, gasping through the rough cotton. Her eyes were watering so hard the catwalk looked like it was underwater, the yellow and green strips of the warning tape running together in shimmering streaks.

"Phoebe!" Jesse was shouting now, his voice tinny and distorted by the little speaker in her ear. "Report. Did you turn the valve?"

"Closed," she managed, her voice coming out as a raspy croak. "Jesse... my eyes."

"Don't rub them. Get out of the well. Head for the Sector Three vestibule. Use the eyewash station by the tool locker. Don't wait for the cycle to clear."

She didn't need to be told twice. She scrambled back up the ladder, her hands feeling clumsy in the heavy gloves. Every breath felt thin, as though someone had replaced half the oxygen in the room with warm nitrogen. Her heart was hammering against her ribs with a fast, fluttering rhythm that made her fingertips tingle.

As she dragged herself back onto the main catwalk, she looked back down the central aisle of Sector Three.

The change was terrifying.

Ten minutes ago, the vault had been a wall of green, vibrant and thick, an unbroken hedge of life suspended between the deck and the ceiling ribs. Now, a gray-brown shadow seemed to be crawling across the canopy. It wasn't moving like a fire, but like a stain spreading on cloth. Fronds that had been reaching for the light banks were curling downward, their tips turning black and brittle, the delicate stems snapping under their own weight. Leaves the size of her torso were folding in half, dumping their pools of condensation into the gutters like tears.

The garden was suffocating.

She reached the heavy pressure door that separated the Sector Three vault from the habitat ring’s inner corridor. The green button on the latch plate was blinking slowly—the normal transit cycle. She hit it with the heel of her hand, threw her weight against the seal as the air hiss cleared, and slipped through into the sterile, white-tiled transition locker.

The air here smelled different. It smelled of ozone, floor cleaner, and the faint, ever-present grease of the circulation fans. It was ship air—stale, dry, and thin—but it didn't smell like bitter almonds.

Phoebe kicked off her boots with two quick jerks of her heels, peeled her gloves off inside-out the way her mother had taught her, and dropped them into the yellow hazardous waste hopper by the door. She shoved her face into the rubber cups of the eyewash station and stomped on the foot pedal.

Two jets of cold, chlorinated water struck her open eyes. She screamed into the porcelain basin—a short, muffled sound—as the chill cut through the burning chemical film. She held her eyelids open with her thumbs, letting the water scour out the grit, counting to thirty in her head.

One-one-thousand, two-one-thousand...

By the time she let up on the pedal, her face was soaked, her hair was plastered to her forehead, and her chest felt less like it had been scraped with a wire brush. She grabbed a rough paper towel from the dispenser, blotted her face, and blinked at the mirror above the sink.

Her eyes were bloodshot, the rims pink and swollen, but her pupils were even. That was something. If they were pinpricked, it meant organophosphates—pesticide poisoning. Her mother’s old medical notes had had three pages on organophosphates, with little hand-drawn sketches of human eyes that looked like dinner plates with tiny black dots in the center.

"I’m out," she said into the mic, her voice still rough.

"I see your transponder in the vestibule," Jesse said. He sounded twenty years older than he had ten minutes ago. "Director Vance is on his way to the shack. The low-pressure sensors in the Sector Three drain lines just tripped his morning dashboard. He thinks we had a valve burst."

"It’s not a burst valve, Jesse. Someone put a tap into the main intake."

"I know that. You know that. Vance doesn't know that, and until we have something more than a twelve-year-old’s sniff test, he’s going to treat it like a plumbing failure and send six mechanics in there with adjustable wrenches to track the leak."

Phoebe pulled a clean dry jumper from the locker and pulled it over her wet undershirt. "They can't go in there without respirators. The stuff... it doesn't just sit in the air, Jesse. It breaks down the membranes. If you take a full lung of that without a filter, you won't be doing any plumbing."

"Tell that to the Director," Jesse sighed. "He’s bringing two aides and the junior logistics officer. They’re already on the central spine elevator. Come down the spiral stair by Bay Four. Don't use the main corridor; there are three maintenance crews heading up with spill kits and I don't want them asking you why your eyes look like boiled beets."

Phoebe unhitched her tool belt from the hook where she had hung it, checking the pockets. Her loupe was there, her multi-wrench, the half-empty vial of mineral oil, and the little glass sampling tube she had grabbed from the emergency kit before ducking into the airlock.

Inside the tube was two inches of the oily greywater from Bed Three, sealed with a red rubber stopper. In the fluorescent light of the vestibule, the liquid looked slightly milky, with little curds of green organic matter suspended in it like curdled milk.

"I have a sample," she said.

"Hide it," Jesse said. "Vance will confiscate it for the central labs, and those clerks won't have the results back before the next rotation. Put it in your pocket and keep your mouth shut until I tell you to open it."

"Jesse, what is Chem-Spec-9?"

There was a long pause. She heard the sound of a drawer opening on rusty slides—Jesse’s bottom desk drawer, where he kept the physical inventory books from the third decade of the ship's flight, the ones written on actual vellum paper that the dry air hadn't yet managed to turn to powder.

"Chem-Spec-9," Jesse said, his voice dropping so low she had to press the earpiece into her skin to hear him, "was what they used sixty years ago, during the Great Mold. When the black spot got into the hydroponic wheat in Ring Two. They tried soaps, they tried copper sulfate, they tried burning the beds with steam. Nothing worked. The spores were living in the sealants between the hull plates."

"So what did they do?"

"They vented the compartments to vacuum for forty-eight hours, then they washed the bare metal with Spec-9. It’s an anti-fungal defoliant. Kills everything with a cell wall. Plants, molds, bacteria, moss. It doesn't care. It breaks down the proteins that hold the walls together so the air scrubbers can sweep the dry dust out through the electrostatic plates."

Phoebe looked at the sample tube in her hand. The tiny green flecks of fern tissue were already falling apart, sinking to the bottom as a fine, grey sediment.

"If that gets into the main canopy," she said, "it won't just be Sector Three."

"If it gets into the primary canopy," Jesse said, "the Vanguard has about four weeks of oxygen left in the reserve tanks. And that’s if we put the entire civilian population on quarter-rations and tell everybody to stop running."

The elevator doors at the end of the hall chimed—a cheerful, two-tone electronic ring that sounded horribly out of place.

Phoebe slipped the sampling tube into the deep watch-pocket of her overalls, tucked her hair behind her ears, and turned toward the spiral stair. The smell of bitter almonds seemed to cling to her skin, faint and persistent, like a shadow that had learned how to breathe.