AI The platform breathed like a sleeping thing. Drips ticked from a cracked ceiling vault, each one a metronome over stale air and old soot. Police tape stretched between iron pillars that once wore enamel signs for destinations no one reached anymore. They’d cut the power to the old rails since the war. Mould scalloped the tiles. Somewhere beyond the dark curve of tunnel, a gust found its way in and tugged at the tape so it quit the silence in little bursts.
Quinn stepped under the cordon and kept her shoulders square. Her boots picked out the dry patches. The station smelled of salt and brass and something sweet that didn’t belong, a scent that rode in from a place with clatter and voices and haggling hands. Her worn leather watch sat snug on her left wrist, face nicked and honest. She glanced at it as if it could tell her anything but the hour.
“Welcome to Camden’s lost and found.” Mercer held two coffees and a grin that didn’t reach his eyes. “Transport cops pulled us in. Vagrant on a live line that hasn’t seen juice since Thatcher. Shop it as a misadventure, go home before midnight.”
“He found a way to cook himself on a dead track.”
“He found a way to die down here. Body’s over there, past the kiosk that stopped selling papers when I started shaving.”
She walked past the kiosk, its shutter rusted halfway closed and stuck, its last headlines yellowed behind glass. The floor told stories Mercer hadn’t read. Chalk dust kissed the edges of the tiles, not from schoolboys or artists. Wheel ruts wore two tracks down the middle of the platform, not bikes, not prams. The ruts paired with dragging scuffs that started and stopped in places that didn’t make sense for a single pair of feet. She let her eyes sweep the arches, the iron rings bolted in patterns along the roof beams. They’d held banners or lights. Someone had scrubbed most of the soot but rushed the job; she saw it under the edges of a pillar where hands rarely reached.
Haynes from SOCO hunched by the body with a camera slung across his chest. Flash. Another. He moved his light without glancing off the skin. That told her he’d already had his fill.
“Hold a tick,” he called when he spotted her. “Don’t trample the art. Our friends were creative tonight.”
Mercer’s boot skidded near a white line of chalk. He hopped back and raised a palm. “Someone likes their geometry. Five points, candles, all the trimmings. Goth kids, drug party, take your pick.”
Quinn took in the pattern. Candles, yes, the stubs flattened where wax had run. But the lines curved inward in pairs, nested arcs that didn’t meet the way kids drew pentagrams. The chalk had been laid in two grades—coarse around the exterior, a finer powder toward the centre that had fused in tiny glassy beads as if it had kissed heat. The burn on the tiles cut clean, not a smear, not a stamp. Someone had drawn wards, but not to invite anything in. A seam of ash traced the innermost curve like the edge of a pot left on a stove too long. What stove lived on a dead platform?
“Kids don’t angle their corners like that,” she murmured, more to the tiles than to anyone listening.
“Look up,” Haynes called.
She did. The ceiling wore freckles, little bursts of char in a circle the size of a man’s arm span. No spiderweb from an arc, no melted conduit. A perfect crown of flecks as if something spat sparks straight down while it hung in place for a breath.
“The BTP lad reckons he took a tumble through that gap there and caught a jolt.” Mercer jerked his chin at the track pit. “Open void, old wiring.”
Quinn crouched at the platform’s lip. Cold air swept the pit. The rails lay dull and furry with dust. A cable sat severed, ends capped. A crisp brown leaf had blown in and lodged under a tie. No scorch kisses. No clean burns. She let her gaze drift back to the corpse.
He lay half on his side like he’d tried to sit and lost interest. Forties, male, double-breasted coat that fit a month ago. His eyes stared past the vault. Salaried hands, nails clean. No grime under the cuffs that homeless wore like rings. The front of his shirt puckered in a shape not made by fist or blade. It had drawn in tight right below the sternum, a dimple the size of her palm. The cloth smelled of metal filings. Her gut wanted to name it; her mind offered nothing she could put in a report without losing a stripe.
“Live wire didn’t kiss him,” she told Mercer . “If it did, we’d have a pattern. He’d go down hard, not curl like a kicked dog. Where’s the foam? Where’s the blistering on the hands?”
Mercer balanced the coffees on a crate and fished in his pocket for a notebook. He didn’t open it. “Overdose? Heart stopped mid-ritual. Mates legged it when the candles burned their fingers.”
“Then his lips would lie a different colour. And they’d take their kit.” She nudged a glass vial near the chalk with her boot tip. Empty. No residue. Another lay on its side by the pillar with a cork that had never met a mouth. A row of smaller stubs lined the edge; not a single wick burned into its own puddle. Someone had placed each one and never lit them, then spun a tale with soot from something else.
Haynes bagged a small object and held it up for her. “Found this in his coat pocket. Not a compass you pick up at the museum gift shop.”
She took the little brass disc in her gloved palm. Verdigris bruised the casing along the hinge where kiss after kiss of damp had pressed in. The face sat etched with lines that curled and broke like mangrove roots. Not Latin. Not any script she’d passed in school. The needle didn’t rest. It shivered as if caught in a draft she couldn’t feel and then tugged to the left, away from north. She turned; the needle swung with a sense like a dog that knew its way home and couldn’t wait to run.
“North’s the other way,” Mercer snorted. “Toy shop rubbish.”
“This isn’t a toy.”
Her thumb found a groove on the crown that matched a chipped nail she’d broken yesterday on a stair rail. Handmade. The etcher had pressed hard where a line crossed another; the grooves felt deeper there, not uniform, not stamped. The back bore a small maker’s mark, a curve like an eyelid with four ticks. Not any hallmark she’d seen. The brass smelled like penny and something more ancient, a dirt that wasn’t loam.
Mercer tapped his pen on his knuckle. “He’s got a wedding band, no indent from a missing one. Wallet’s gone, phone’s gone. Robbery gone sideways. The chalk? Party nonsense. The compass? Tourist tat. The burns? From a flare, maybe. We’ve had kids set them off in stairwells.”
Quinn let the needle pull her a step. It pointed not down the tunnels but toward a bricked arch half-hidden behind posters that wished commuters a happy Olympics. The topmost poster had been peeled back and stuck in place with fresh paste. The mortar around the arch was newer than the rest of the platform, paler, smoother, tucked into the joints in a hurry by a hand that had more to do that night than point a trowel. A thin seam of black edged the lowest bricks, like breath had crept under and hadn’t found a way back out.
“Who bricked that?” she asked no one.
“The city,” Mercer offered. “Sealed the echo off so kids don’t get in.”
“Kids already got in.”
Haynes cleared his throat. “Transport says that arch opens to a service tunnel that branches to, quote, disused storage. They’ve lost the key.” He lifted his camera again. “Funny sort of keyhole. No plate, no handle.”
Quinn crouched by the arch and pressed her ear to brick. Cool. Dense. Something on the other side pushed the air through a pinhole. A faint thrum, not mechanical in rhythm, not the endless hum of a distant generator. More like breath from an empty lungsack, drawn and held. Her jaw clenched . Three years hadn’t ended that sound in her head, the rush of nothing that came before Morris stopped answering. Her tongue found a scar inside her cheek where she’d bitten down on prayer and found iron.
“Mercer, who called it in?”
“Neighbour heard noise through a grating on the street. Clatter, voices. Then a shout. He peered down and saw a lamp glow and then nothing. Thought it was a squat. Phoned it in when the glow didn’t come back.”
“Voices?”
“Shouting. Could’ve been two, could’ve been twenty. He was above ground with traffic in his ear. He’s half-deaf from motorbikes.”
Quinn straightened. Her knees popped. The compass tugged at her hand like a dog at a lead. She pressed the crown; the needle jittered and swung hard toward the arch again. Not magnet. Not metal. It wanted the hollow.
Footsteps on tile echoed from the stairwell. A woman’s voice carried before she cleared the bend. “Tell me you aren’t making me crawl through another Victorian sewer.”
Eva Kowalski hugged a leather satchel to her ribs with one hand while the other brushed a coil of red hair behind her left ear. Round glasses fogged as the station’s cool breath kissed warm lenses. She blinked at the chalk on the floor and slid to a halt with a boot squeak.
“You called the museum,” Mercer muttered. He didn’t quite hide the relief . “Please tell me that’s legal.”
“It’s a consult,” Quinn answered. “We get arcane scribbles; I ask someone who reads more than gang tags.”
Eva wrinkled her nose at the scent. “This place wants to tell stories.” She tilted her head at the chalk. “And this one’s not satanic. People always draw pentagrams upside down like they think they’ll conjure a demon if they get it wrong. This is different.”
“Give me something I can use,” Quinn told her.
Eva swung the satchel round and tugged out a notebook, though her gaze never left the lines on the floor. “The outer arcs create a kind of net. The inner curves tuck under and through. You don’t invite something with this. You keep a door from slamming open. It’s a ward. See these crosshatches at the nodes?” She tapped a spot near a tiny bead of fused chalk. “Heat licked it. Not fire. More like static that went hunting for a ground and missed.”
“Missed and hit him.” Mercer jerked a thumb at the body.
Eva crouched, kept a hand back to avoid brushing a line. “If it hit him, he’d be marked differently. That pull under the sternum looks like push, not pull. And the pattern on the ceiling… that’s scatter. Sparks thrown off a wheel. But there’s no wheel. Who has a wheel on a dead platform?”
“Stupid question,” Haynes called from the body. He jotted something on a label and sealed a bag. “We get stupid questions down here.”
Quinn held out the brass disc. “What’s this?”
Eva took the compass in two fingers and didn’t pretend she didn’t feel the pull. Her mouth thinned. She turned the face to catch Haynes’s flash, and the etching lifted into light and shadow with a depth that punished the eyes. “This is not a navigational tool you buy at Portobello. These are ward marks on the face. Someone wanted this thing not to lie. The needle’s not pointing north. It’s pointing at—”
“The arch,” Mercer finished, because the needle made his choice for him .
Eva looked at the mortared curve. “My boss would have kittens.”
“Your boss not here,” Quinn told her.
“She’d still have kittens in my head.”
“Can you place the pattern?” Quinn nodded at the chalk. “Not a pentagram, not a kid’s take. What is it?”
“If you made me bet, I’d say someone laid a holding pattern based on warding sigils for rifts. Old variations from Central Europe, nineteenth century, misremembered by someone who learnt family lore instead of books. And then they laid modern flourishes on top. That makes it messy. But whoever did it knew enough to mark the nodes. They expected something to push through. They tried to hold it. It pushed anyway.”
Mercer whistled through his teeth. “You dragged me out over a ghost story.”
“Ghosts don’t leave scorch freckles on ceilings in neat rings,” Quinn cut in. “And they don’t carry brass toys that point at bricked arches.”
“We’re not equipped to unbrick an arch,” Haynes muttered. “We can call a council crew. Wait three days. Fill out forms about heritage tiles.”
Quinn crouched low and scraped her glove through a bit of wax that had pooled at the base of a stub. It broke with a brittle snap. The wick inside had never burned. She moved the base aside and found a thin sliver of bone under it. Carved. Polished from handling. She lifted it to light. A hole near one end, handy for a cord. Tiny notches along the edge designed to catch thumb skin. The sliver weighed less than it looked, but it wore a patina that belonged to old ivory and too many fingers.
“Token,” Eva breathed. “They used to carve those for entry to... places. Not museums. The kind of places you don’t talk about till you’ve met the doorman twice. They take one as a toll. Keep it if you misbehave.”
Haynes bagged it while his brow furrowed . “Entry where?”
“A market,” Eva murmured without meeting his eye. “A hidden one. Don’t ask me for a map.”
Mercer shifted his weight and knocked something with his boot. Coins rattled and ran in a shiny arc, a handful of pound coins too clean for underground. They stopped against a groove in the tile shaped like a cartwheel had chewed the edge for a season. He bent and picked one up. “Someone dropped their cab fare while playing wizard.”
“Or someone salted the floor to shout thief and hide the bit they didn’t want us to see.” Quinn scanned the platform again. Cardboard in a corner, but not the kind anyone slept on. White dust smeared on the edges of a crate mark, but not on the crate itself. She closed her eyes enough to unsee, then opened them to see in layers. Stalls had stood here recently, not months ago. Twine had tied banners to those roof rings and wore grooves thin into the rope. The smell of clove and cut metal and fish oil lapsed under the dust. You couldn’t fake that in an hour with candles.
“Full moon last night,” she said to her watch face, to the memory of an over-bright sky over the river when she crossed it. “If you believed in clocks other than this.” She tapped her watch .
Mercer rolled his shoulder. “You think what, boss? That an underground market appeared on a defunct platform like it’s a Dickens novel? That our man here bought one too many cursed teapots and dropped dead when the carriage turned back into a pumpkin?”
“Names in your pocket,” she told Haynes. “Anything?”
“Nothing on him except the compass and lint. No ID. Wedding ring, nice watch , cash gone. Pockets turned, neat hands. Whoever turned them didn’t like mess.”
“Look at his shoes.” Quinn leaned in and pinched heel leather. Italian. Thin soles. The tips had scuffs that drew an arc like he’d braced and slid. Gravel dust clung only to the left edge. He hadn’t run. He’d been moved a little, then left.
Mercer rubbed his jaw. “Why move him? Why not dump him on the stairs and let the first drunk stumble over him?”
“Because he died here, and they didn’t want to carry him past whatever door they used.” Quinn let her gaze snag the arch again. The needle in her palm never tired. It strained for that brick like a hound.
Eva knelt beside the nodes. “The pattern breaks here.” She pointed. “This line’s smudged at the edge, not scuffed by a shoe. Someone brushed it with a sleeve. In a rush, not a dance . Whatever they did next, they did fast.”
“Neighbours heard a shout,” Mercer reminded them. “Then silence .”
“Shout like anger, or shout like instruction?” Eva asked. She tucked her hair behind her left ear, then caught herself with a little huff. “Focus. These wards would hold for a minute on a good day. If something pressed hard, they’d fracture at the thinnest point. Right here. Look.” She touched the fused bead. It had a shard of something black in it, like a sliver of obsidian. “This isn’t chalk. It’s glass. Glass that was never in a bottle.”
Quinn held the sliver of bone up with the compass in the same hand. The two looked at home together. The needle jerked when she brought it near the bone, an excited twitch. The etched face drank the ceiling’s light and offered nothing back. She tasted metal again.
“Get me a thermal on that arch,” she called. “And someone call the council, the transport museum, whoever claims the keys. We’re not busting heritage, but we are not waiting three days .”
“You want to hold court with a heritage officer at midnight,” Mercer groaned. He watched the needle. “He won’t like this place either.”
“Anyone who likes this place’s just wrong.” Haynes snapped a photo of the compass in her glove. “For the file.”
Footsteps sounded above again, heavier now. Voices filtered down, official and tired. Quinn planted her feet dead centre of the floor, between the chalk and the arch. The arch breathed like a throat behind a door, and somewhere, a candle that had never burned lay on its side and waited for a light that never came. She lifted her head and took in the station whole, the grooves, the hooks, the soot. The story tried to sell itself as a drunk’s end on cold tile. The tiling fought back with its own version and found an audience in her.
Mercer picked up the spare coffee and offered it over with two fingers. “You going to tell Bossman upstairs we’re dealing with antique smugglers who draw pretty circles to confuse the uniforms? Or you going to keep the ghost bit off the ledger and give him the robbery angle he wants?”
“I’ll tell him the body didn’t match the room.” She took the cup and didn’t drink. “And that the room didn’t match anything. That should earn us an hour.”
“One hour,” Mercer nodded. “To find a key we don’t have, and a door that doesn’t want us.”
Eva still hovered by the chalk, hair lit copper by a SOCO lamp. “Not a door,” she murmured, eyes on the compass needle that twitched against brass. “A seam.”
Quinn didn’t answer. The watch on her wrist ticked her pulse back into something steady. The arch waited with the patience of brick. The compass needle wanted. She set the brass disc flat on her palm and let it pull. She took a breath that tasted of old smoke and clove and made a choice with her feet.