AI The stairs down to the platform sweated rust. Generators throbbed under the vaulted ceiling and threw hard white over the cracked tiles. Tape fluttered . A fox skulked on the far track and vanished between sleepers the moment boots clanked.
Quinn checked her watch and dropped into stride. Closely cropped hair caught the glare, her shadow long over the old advert boards where 1930s smiles peeled away from brick. The smell hit with the damp—the metallic bite of old water layered with something sweet, something like fennel baked into soot .
Colin Bray waited by a transit case, hands in the pockets of a wax jacket that had seen rain and indifference. Stubble framed a grin that didn't reach his eyes.
"Thought you'd send a junior to this one."
"Thought you'd clear the access before you called," Quinn stepped around the evidence cones and nodded toward the body. "Who found him."
"Urban explorers," Bray tipped his chin toward two figures wrapped in foil blankets near the stairwell, talking at the uniforms. "Said the gate was open. We checked—it wasn't jimmied. Bodies don't open gates, so we've got a friend."
Quinn crouched. The man on the platform wore a grey blazer over a shirt gone black at the collar with grime. Mid-thirties, maybe older under the city wear. Hands callused, nails rimmed with ash. A thin slit along his right forearm stopped just short of the wrist. Not a clean cut—more like a burn that never bubbled. A smear of maroon under the left shoulder told of a drag.
She didn't touch him. Her eyes moved: the dried sheen of his lips, the faint darker tide line at the back of the neck. Lividity sat where it shouldn't if he'd died on his back.
"He's been moved," Quinn's voice skimmed the platform .
"Or rolled," Bray watched her . "He could've thrashed. Junkies do."
"Find me a needle, a spoon, anything," she rose and walked an arc around the cones. "Any vomit."
"He's clean. One wallet, no phone. Wallet had thirty quid and a discount card for a butcher in Finsbury Park. No track marks. Could still be fentanyl."
Quinn knelt again near the boots. The soles carried a fine powder. She pressed a gloved finger into a trackside dust drift and brought it to her nose. The sweet note returned, undercut by iron. On the tile near his waist, an outline sat where something rectangular had rested—the ghost of a wooden crate or a box lifted in a hurry, the clean shape surrounded by dirty stipple.
She looked up. "How many of those rectangles did you count."
Bray blinked slow. "What rectangles."
"All of them," she walked, straightening . Cones marked a ragged alley between stains. She traced with a toe the end of a scuff that began nowhere and ended with a gouge like a chair leg. Another two, side by side, set the width of an aisle. To her right, a crescent of wax had run and cooled on the tile lip of the track. The drip lines stacked in a ladder. She smiled without humour. "Stalls. They had a stall here. More than one. Row down the middle, backs to the wall. The wax forms a path where heat met cold. You can see where fumes pulled toward the tunnel mouth."
"You could sell tat here," Bray shrugged. "Any bunch of kids with a camping stove and a crate of vapes can make a mess. Camden's above us. You're painting Spitalfields from dust and candle grease."
Quinn walked to the edge, crouched, and laid a hand on the steel of the near rail. It held the night's damp like a memory. Between the sleepers, a sliver of off-white caught the generator glare. She reached into the filth and came up with a carved bit of bone no bigger than her thumb. A hole ran through one end. Notches scored both faces in a pattern, five, then three, then a longer cut. It had the worry-smooth of a thing carried in a pocket and thumbed.
Bray peered. "Chicken bone. Lucky charm . Street boys wear them."
She held it up to the light and turned it. "This wasn't eaten. It's carved. The edge shows file marks. And it's clean. He dropped it fresh."
"It looks like any tourist tat you buy on the lock on a Saturday."
"Bag it," she passed it to a scenes tech who materialised with an evidence envelope poised. "Photograph the notches on both faces before print powder ruins them."
She moved back to the body, and this time slid a hand under the blazer, pushing gently . Something small knocked against her glove. She withdrew a brass circle, weighty, palm-warm from the man's last heat. Verdigris ran in veins across its casing. The glass had a scratch that crossed a series of etched symbols, not letters but knots and hooks that made the eye skate. The needle didn't rest on north. It didn't rest at all. It vibrated around a fixed point and then settled, sharp and sure, not toward the stairwell, not toward the tunnel mouth the tourists had used, but toward the blind curve where the wall met the old service door bricked up decades ago.
Bray's voice carried a chuckle. "Victorian toy. The magnet in it goes with the iron in the rails. Pointing at the only straight bit of metal you can find in a place like this."
Quinn walked with it. The needle strained against its hub as if it had weight . It didn't swing toward the rails when she brought it close. It dragged back to the corner and held like a pointer on a child's game. She stopped where the old tile had cracked into a star. Air pressed cold against her cheekbone. She drew two fingers across a patch of soot and the motion lifted a clean spiral like she'd wiped at a breath mark. A scene tech behind her shone a sidelight and tiny cuts in the tile's glaze glowed a dull blue.
"Graffiti," Bray leaned into the beam. "Kids love old stations. They love sigils too. WitchTok's full of this rubbish."
"Get the UV," Quinn didn't raise her voice. "Photograph every mark from waist height to shoulder. The etching depth differs. Some are fresher than others."
He blew out his cheeks but waved, and the tech slipped off. Quinn held the compass in the halo and watched the needle pull. It didn't waver. She looked at her watch and then at the far tunnel, where the generator hummed and the fox had gone. She listened. Under the hum, somewhere beyond the platform curve, air whispered. Not the draught of a passing train, not here. A pelvic ache of moving space. The hairs on her hand lifted under the glove.
Bray watched her watching. "We've got a dead man in a wasted station and you want to take pictures of chalk."
"We've got a dead man who didn't die on his back and got moved into a place wiped clean by a moving crowd," she flicked a finger at the wax drips. "Whoever traded here did it often enough to mark the tiles. They packed up in a hurry. He got left. Not kids."
"This—" Bray pointed at the etchings under the UV the tech brought back, a mesh of intersecting lines that looked calculated only if you'd lived a life of lines. "—counts as calculated to you. It looks like nonsense."
"It looks like someone knew what those lines meant," Quinn watched the UV pick out the pattern. The centre sat at shoulder height. The green wash on the brass in her palm made the needle a dark slash. She held it closer and the needle fought to align.
Bray snorted. "You using a compass in a tube station to look for what, the sea."
She let the tech bag it. "Find me the access they used. Gate wasn't forced. The locks look clean. Go out to the cul-de-sac above and ask the council if they've got any scheduled works this end. Whoever came in had a key or a code. Or another door."
"We walked the line," Bray jerked a thumb toward the shadow where the tracks slipped into black. "From Chalk Farm in. Both sides. No holes. CCTV's dead this deep. You won't like this one, Harlow. It's a squat with a posh twist. Pop-up sale, pushy kids with trust funds. He got in the way, they ran, then your explorers found him with his museum piece."
Quinn turned her gaze to the scuff marks again. "No heel prints that match Dr Martens. No flakes of glitter, no sweet wrappers, no nitrile gloves from kids anxious not to touch. Who burns anise oil in a camping stove. Who lines their stall legs with cloth to stop the scrape." She pointed at the faint cloth impressions around four circles on the tile, a ghost fringe where heat had made the weave print. "They expected to come back. They didn't expect police."
"You make a temple out of camping."
"Bag his coat," she crouched again and lifted the blazer cuff with tweezers. A line of soot ran along the inside seam at the wrist, interrupted by a set of tiny calls on the skin, half moons, four along the forearm, one at the crook. "When this hit him, the heat came in crescents. Not a stove. The skin didn't crack like a flame burn. He got near a field. Or a ring. Or something round and fast."
"How close do you have to get to a paraffin ring to make that," Bray kept his tone casual.
"Closer than you'd want to when sober. He didn't run. Look at the knee." She moved to the left leg and pressed, exposing a patch of graze on the kneecap. It held grit that matched the track ballast. "He went down there, not here."
Bray's mouth flattened. "You think they pulled him here?"
"They dragged him up. See the shoulder smear leading to the edge? Then they shifted him by the arms and his head knocked there—" she tapped a tile star with a gloved knuckle "—but there's no scalp blood on that line. He was dead by the time they moved him."
"Forensics'll tell us time and tox. You're building a story on dust."
"Every story here is dust," Quinn straightened. "Who's our array upstairs."
"Uniforms, for now. CSU's on the way with the van. Your favourite pathologist's at Highgate and will hate this place."
"Bring in a camera that can do a proper grid. And get me a portable barrier. I don't want any stray air from up top shifting what's left."
"Air," Bray smirked. "You're acting like a storm's going to open."
"Don't be wet."
He lifted palms in surrender, walked off a pace, and flagged a PC.
Quinn stepped back into the spill from the generator light and took out her phone. The museum number lived in her brain like a song she hated. It rang twice.
"British Museum, Archives."
"Kowalski."
Silence, then a click change in her voice when she recognised Quinn. "You only ring at inconvenient hours."
"You like inconvenient. I need your head for two minutes."
"I charge extra when you sound polite."
"A token. Carved bone, thumb size, hole bored through the end. Notches in runs. Five, three, then a longer. Could pass as folk. Doesn't feel like folk."
Eva made a soft sound, quick thought turned into breath. "You at the place under Camden."
"You heard something."
"Stories move faster than the police radio. You're in an old station with new friends and one body. You found a sliver of something that got rubbed in a lot of pockets."
"Call it that, if it helps."
"Bone like that works two ways—tally, yes, or a pass. People count with cut marks, sure, but they don't drill a hole unless it hangs. If it hangs, it goes to a neck or a keyline. People who play at markets—" Eva paused. "—use bones to keep the gatekeepers honest."
"Gatekeepers," Quinn watched the compass bag seal and wrote the exhibit number in her notebook. "You mean ticket inspectors with worse table manners."
"If you want it easy. The notches describe something. You'll want to measure the distance between them and the spacing. Some sets name people. Some name places. Some name nights."
"It smells like anise down here."
"Then it's not kids. And if you found a brass thing with writing scratched into the face—symbols you hate to look at—don't stick it to a magnet and giggle when it moves."
"Already laughed," Quinn watched Bray lean in with a uniform and point toward the bricked door. "It doesn't like the rail. It liked the wall."
"You want it in a box. Don't drop it. Those bruise easily. They call them compasses, but they're not for north."
"For what then."
"For elsewhere."
Quinn let the word pass. "Do me a favour. Send me a page on tokens consistent with gate control in temporary markets. Use words the prosecution won't laugh at."
"You've got my rate sheet."
"Bill me," she ended the call before Eva could needle and slipped the phone back into her coat.
Bray wandered back, hands empty now. "So your museum friend thinks it's a circus."
"We both know better than to call it that," she ran a hand over her hair and scanned the platform again. A basin of city. Old grime, new ghosts. "What's above us. Directly."
"Scrap yard. A little car lot. A block of flats with a corner shop that sells bread out of date and lottery tickets that never win."
"Get someone up there knocking. Ask for anyone who heard moving vans after midnight. Ask about men with hand trucks and cloth-wrapped cases. Ask about candles."
"Candles?"
"Or lamps. Or braziers. Or anything that makes heat steady and low. Ask about buyers in clothes that don't fit Tuesday morning at work."
He smirked. "You want Boho chic or funeral suits."
"I'll take either. And send uniform to Highgate. Find DS Morris's file," she caught herself, jaw tightening. "Find comparable shows of force in closed spaces. Look at the scorch."
Bray's face shifted, sympathy attempted and then abandoned. "You sure you want that."
"I'm sure I want this to look less like a squat and more like what it is. Start with access. End with cause."
He nodded and went.
Quinn stepped to the bricked door again. The tech's UV traced the erratic lattice. Under it, the spiral picked out earlier seemed less random, more like coordinates if you stared long enough. She didn't give it the gift of a second longer. She pointed with her chin.
"Get me scale shots. Every line. Every corner. Then dust for prints at knee and below. People steady themselves when they push through something heavy. Their hands go low."
The tech grunted assent and moved in with a ruler.
Quinn looked back to the body. The forensics doctor crouched now, careful and methodical , gloved hands reading skin. Across the rail, a uniform yelled and a man in a hi-vis waved from the far tunnel, something about water ingress and permits. Somewhere in the dark, a drip counted slow seconds. The compass sat inside its bag on a transit case, needle steady as a glare.
She pointed at a constable. "You—get a box of swabs and go the drains. Anything that looks like bone or carved wood, you treat it like it's a name. Do not kick it down the pipe."
"Ma'am."
"Bray," she caught him before he went up the stairs. "Those explorers. What did they say about light down here. Any."
"They said it looked like a market the morning after a storm. Stank like licorice with a cough. And that someone laughed when they came in and then went quiet. You know how they talk. They sell stories to get free coffee."
"Get their video. They always film. Even when they don't admit it."
He nodded once and took the stairs two at a time, voice already pitching up to get someone's attention.
Quinn rolled her shoulders and let the station breathe around her. Unusual location, wrong evidence, colleagues who wanted it neat. Nothing here lined up as neat. She took one last look at the thin crescent burns on the man's arm and the black trace under his cuffs. She clapped the powder from her gloves into a bin bag and turned to the stream of incoming bodies hauling tripods and cases.
"Mark the aisles," she told the first. "You'll find them where the tile is cleanest. Then build me their market."