AI Harlow caught the constable's wrist before his glove smeared the bone-white ring.
Careful, she said, then stepped past him into the hollow of the platform. Stalls listed against tiled pillars, tarpaulins slumped like shed skins. The air carried spice smoke and the tang of copper. Strings of dead bulbs drooped between ribs of brickwork. Someone had tried to clean, to erase, yet everywhere she looked the place told on itself, char and wax and crushed herbs ground into the cracks.
Park raised an eyebrow by the body. He had his suit jacket off and his tie tucked. His latexed hand hovered near a scatter of glass vials in a shallow crate.
Rough night, Quinn.
She crouched. The corpse leaned against a pillar under a handwritten sign that read Cuts, Curses and Clocks, the paper bled by something dark. Mid thirties, male, olive skin, shaved head. Someone had arranged his hands on his lap. Broken capillaries webbed the whites of his eyes. His lips hung open.
Not my night, she said, and slid a torch beam across his face. Teeth intact, tongue swollen. The light picked a flash of creamy grey between his molars. She angled the torch, then pinched on a nitrile and reached in. A small polished token kissed her fingertip.
Bone, Park said.
She rubbed it against her glove. Smooth. Tiny script scratched into one face, an alphabet she did not recognise at a glance, then a crude symbol on the other, a crescent hooked through a key. She held it flat on her palm.
You see that on the way in?
Park shrugged. We pulled a dozen of those out of bags. Party favours. University lot put on a show, someone drops, mass panic, a stampede through a service door, and they leave their toys.
She looked up at him. Toy witnesses run faster than panic.
He smiled with half his mouth. We will find them. Cameras caught figures through the grilles. Fancy cloaks, silly masks. One of the uniforms said performance art. They bolted when a bloke died. It fits.
She let the token sit warm on her glove. The bone-white ring on the floor did not fit. It circled the space where the crate lay scattered. The chalk had grit in it. Not classroom stuff. She squatted by the line, nose a handspan over the surface, and let the torch skim. Tiny dark flecks caught the light, densely packed where the line curved around the pillar.
Not chalk, she said.
Park clicked his tongue. Talc then. Blood spatter analysis will tell you everything and a bedtime story.
She dipped one gloved fingertip through the line and brought up powder. Iron prickled at her tongue though she had not tasted it. Bone ash. Oily blacks where fat had kissed flame. She lifted her finger to her nose.
Whoever drew this worked hot, she said. Not a student.
Park's tone changed. Occult then.
She clicked the torch off and stood. The dark felt thicker for a second, then the scene details asserted themselves. A tar line ran in an arc a yard outside the ring, still tacky. Bits of brown resin, crushed like amber glass. Wax drips dotted the tiles, but the drips massed on one side of each puddle, as if dragged in one direction without tilt.
Your stampede did not disturb the wax, she said. Your stampede missed the ring. Your stampede stepped here and here, and not here.
Park followed her beam as it traced shoe prints. Trainers, cheap, the soles with star treads. A set of boot prints, deeper, a chunk missing from the outer heel of the right. They came in from the tunnel side, crisscrossed the stall, stopped shy of the ring, then doubled back. No smears, no drops of fresh blood across them.
He bared his teeth. They tiptoed around the magic circle. My lot will send them a thank you card for preserving evidence.
Her jaw tightened. The old anger rose and she put it down in the neat little box she kept for it, like she had been taught . Not tonight. Not the same mistake as before. She moved the torch to the man's shoes. New leather soles, expensive, and a tiny grit caught in one welt that had not caught in the other. Glinting green. She levered it out with her nail, a flake of oxidised metal, Verdigris.
She lifted his coat flap. His inside pocket bulged. She slid her hand in and pulled out a small brass compass. The casing wore a crust of green, the kind she saw on old railings by the river. The face was crowded with tiny sigils etched between the points. The needle did not settle. It trembled , a faint quiver like a muscle under skin.
Park leaned in. Souvenir from a museum stall.
She felt the weight of the thing, how it pulled a fraction toward her wrist. Not magnetism. Something else. Her heartbeat thudded and the old case pressed at her. She glanced at her watch . The leather had cracked along the edge but it kept perfect time, a habit she had never dropped. Order, even in holes like this.
She set the compass on the floor inside the ring. The needle snapped to point past the pillar toward a bricked arch with a teal enamel sign, Letters lost to chips. Where the old service tunnel curved away, someone had plastered brick over brick in neat bonds years ago. Her torch fell on the seams of that wall. Mortar smooth, undisturbed. A spider had sheeted the lower corner and dust lay thick as felt on the sill.
That, she said, and nodded toward the blocked arch, is not an exit.
Trespassing on history now, Park said. Dead bloke, costume party, a token in his mouth. You will tell me it is a black market sacrifice, and I will tell you about ketamine and a heart that gave up.
Harlow straightened. She let the back of her glove brush the pillar behind the corpse. Rough indentations notches at hip height, two to each side at even intervals. Hooks had hung here. The sign above them swayed in the air currents people made with their movements. Cuts, Curses and Clocks. The third word struck her as more than decoration. A torn strip of cloth snagged on a nail glimmered with tiny stitches, fibres of silver thread woven through.
She crouched again and pulled the corpse's right hand closer, rolled it palm up. The lifelines were mottled . A knife had burred the skin in a straight, careful cut down the centre, not across the wrist, a controlled bleed. Dried blood ringed it, thick and black.
Self-inflicted?
Neat, she said. Your student bled him like a sheep. You see the edges, clean, one pass. I want the knife. Not serrated. And he is dry inside, but the pool under him is small. If he died here, I missed all the blood that left his body.
Park nodded to the ring. It soaked into your circle of crematorium leftovers.
She let the comment hang. She took a step and felt grit give under her sole. She crouched and palmed a handful of crushed crystals from under the tarpaulin edge. Camphor. She rolled a piece and the smell hit the back of her nose, sharp and medicinal, and the memory of formaldehyde in a college lab stabbed into the present and stuck. She put the crystals in an evidence bag, then walked the edge of the ring again.
On one side, a gap interrupted the line by an inch. Not a break. The drawer of the circle had paused, juddered, then continued. Her torch picked faint scratches on the tile where something heavy had dug in and turned. She moved along that vector with the light.
At the end of the vector, by the low wall of the old track bed, shoe prints ended in a cluster, print on print, the star treads churned together. Then nothing. No smear of grease, no imprint on the dusted service steps. No tumble into the bed, no handprint on the ledge. The prints ended as if picked up.
Park watched. Kid on someone's shoulders, he said. They had fun with us.
She walked to the service door. The chain lay through the handle. The lead seal that Estates used to identify tampering hung unbroken, stamped with last month's date. Cobwebs frilled the hinge and powdery grey clung to the corner inside the frame.
He did not run that way , she said. I want your masks from the cameras. I want a list of every university society with keys to anything down here. And I want a word with whomever called this in.
Park gestured with the hand not holding his notebook. Witnesses corralled over there. Your favourite kind, three teenagers who discovered morality between shots. And her. He pointed at a woman sitting on a flight case by the broken kiosk. Curly red hair coiled in a loose bun, round glasses, freckles like a sprayed mist across her nose. A battered leather satchel lay at her feet. She looked like a librarian who had taken the wrong turn into a boot sale and refused to admit it.
Harlow walked over. The woman stood before she asked.
You the one who dialled, Harlow said.
The woman nodded. Her hand went to tuck a curl behind her ear and stopped halfway, as if she had trained herself out of habits in rooms full of eyes. Eva Kowalski, she said. Research assistant. British Museum.
You work with restricted texts then, Harlow said.
Archival handling, she said. Among other things.
Tell me about your other things.
Eva swallowed. Her voice did not shake. A friend messaged me with an address, a place to find a book you cannot get on a shelf. I came to look. When people screamed, I ran to the stairs and called 999, then a uniform told me to sit.
Harlow looked at her shoes. Sensible trainers with a film of dust on the toes. Not the star-tread pattern by the ring. She scanned the satchel. Scuffs, ink blotches, and a new tear along the bottom seam that looked recent. Threads strained white.
You got what you came for?
Eva kept her eyes on some point a foot left of Harlow's face. I did not pay. They packed up the table. Someone shouted fire. The lights went. I lost my friend. She will text. She always does.
Who sent you the address?
Eva blinked. I cannot give you that.
Harlow watched a small tremor move through the tendons on Eva's neck and counted three heartbeats, then four, and let the silence do work.
Eva met it. She shifted her weight and the satchel bumped against her shin with a thunk too solid for paper. Harlow glanced down. The satchel's flap sat crooked, as if something square fought the leather. The bone token in her pocket warmed, or she imagined it. She filed the satchel under Later.
She stepped back to the ring. Park had wandered over to the corpse and muttered to a SOCO about lividity stopping at the waistband. The compass on the tile still pointed at the false wall in that urgent, quivering line. Harlow bent and turned its bezel, aligning a sigil that looked like a reversed letter R with the needle point. The vibration steadied. She lifted it and walked the arc again.
At the gap in the bone ash line, the needle seized and pulled her wrist towards the bricked arch as if attached by a string. She knelt, held the compass in the space of the break. The needle stopped trembling. It locked true.
She spoke without looking. Park, clear the platform.
On what basis?
On the basis that if I am wrong, you lose three minutes, and if I am right, we all walk out with our skins still wrapped.
She heard the scuff of his shoes and the impatient clap of his hand for the uniforms. Boots moved. Voices called. People grumbled. Eva stood up from her flight case and picked her satchel off the floor and cradled it to her.
Harlow eased her gloved finger into the gap in the ash and traced the exact place where the line failed. Tiny scorch marks pricked the tile in a crescent that did not match any other around the circle. A handmade flaw. A keyhole.
She placed the bone token on the tiles at the edge of the gap, the crescent and key carving face up, and set the compass on top. The needle hummed again, a little song in her hand bones, too high for anyone else to hear unless they were touching. The metal warmed under her palm.
Park's voice came from somewhere behind. Quinn, do not, and the rest of it drowned as the compass needle spun and stopped, dead.
The air inside the ring thickened, as if the platform exhaled syrup. Candle stumps that had refused to drip now sagged at once and sent fat tears to the tile. The wax followed an invisible slope towards the flaw. A hairline in the mortar at the bricked arch lit red as if a coal sat inside it, then cooled back to dead brick.
Harlow stood and stepped back a pace. The compass skittered on the tile as if pulled by thread and stopped with a clink against the edge of the ring. She heard a rattle like teeth in a glass jar. The bone token shivered, spun on its axis, stopped with the key pointing at the arch.
Park swore. The uniforms shouted for everyone to hold. Somewhere, the teenager witnesses squealed in a way that was not theatrical.
The false wall bowed. It looked like breath from a lung inside the brick. Mortar dust feathered out and hung in the air . Harlow could feel the hair on her forearms stand under her suit jacket. The old anger opened its eyes in its box and stared.
She put her palm up to Park without looking at him. Stay.
The bricked arch cracked on the right side down three courses, a precise vertical tear. The crack ate its way into the grout and met the floor with a knock like a door closing on carpet.
The last thing she registered before the bricks moved was Eva stepping forward with the satchel clutched and her mouth set in a line that belonged in a library when someone mishandled a folio.
The wall bulged once and burst, not outward in an explosion, but inward with a fall, like a curtain lifting . Beyond it yawned not the black of a disused tunnel but a cut through the world that showed no brick on the other side. Air poured through with the scent of cold stone and something mineral and wrong. A shape leaned in that did not belong to trains or London or the sensible rules she made herself follow.
Park said her name once.
Something reached for the circle.