AI "Don't step in the sludge, Miller. Unless you want to lose that boot."
Detective Harlow Quinn shone her torch beam onto the kaleidoscope of viscous fluid pooled on the cracked tiles. It shimmered with an oil-slick rainbow sheen, but beneath the surface, faint luminescence pulsed like a dying heartbeat. It smelled of ozone, burnt sugar, and something copper-sharp that coated the back of the tongue.
"It's just chemical runoff, Guv." DC Miller sidestepped a pile of rotted wooden palpitations, his voice echoing too loudly in the subterranean silence . "These abandoned Tube stations are full of it. Asbestos, grime, god knows what leaking from the sewers above."
"Sewers don't run uphill." Harlow crouched, her knees popping slightly —a reminder of forty-one years, half of them spent chasing shadows in London’s gutters. She pulled a glass vial from her kit. With the precision of a bomb disposal technician, she skimmed a sample of the goo. The glass hissed. "And sewage doesn't glow."
"Meth lab, then," Miller countered, playing the torch over the curved, soot-stained walls of the tunnel. "We're fifty feet under Camden. Perfect spot for a cook. Ventilation's rubbish, though. Explains why they scarpered."
Harlow stood, smoothing the crease in her trousers. Her salt-and-pepper hair was cropped close, practical, contrasting with the sharp, feminine angles of her jaw. "They didn't scarper, Miller. They packed up. There's a difference."
She walked further into the hollowed-out station. This wasn't just some forgotten maintenance shaft; the architecture was Victorian, the tiling ornate despite the layers of filth. It felt heavy. The air pressure was wrong here, pressing against her eardrums like she was underwater.
"Look at the dust," she commanded, pointing her beam at the floor.
Miller squinted. "Footprints. Lots of 'em. Trainers, mostly."
"Pattern," Harlow snapped. "Look at the pattern."
The dust wasn't just disturbed; it was swept clean in perfect circles, arranged around makeshift stalls that were no longer there. Rectangular voids in the grime marked where tables had stood hours ago.
"Market stalls," Miller muttered, realization struggling against his skepticism. "An underground rave? Pop-up shop?"
"Something like that."
Harlow moved to the center of the largest clear space. She felt it again—that prickle at the base of her neck. The sensation she hadn't felt since Morris died. The feeling of being watched by something that didn't have eyes. She checked the worn leather watch on her left wrist. Midnight.
"Found something," Miller called out from a dark alcove near the tunnel mouth.
Harlow joined him. He was nudging a small object with the toe of his boot.
"Careful." She pushed past him .
It was a small, round disk, carved from something porous and yellowed. A bone token. A crude rune was scratched into the surface.
"Keep away out," Miller interpreted. "Gang tag. Told you. Drug territory."
"It's an entry ticket." Harlow bagged the token, fighting the urge to let her skin brush against it. It felt cold, colder than the ambient temperature. "And this isn't a gang tag. It's a ward."
"A what? Like... for ghosts?" Miller chuckled, but the sound died quickly in the oppressive dark.
"For keeping things out. Or keeping them in." Harlow turned her back on him, scanning the alcove. Her light caught on something metallic wedged into a crack in the brickwork.
She prized it out. A brass compass, heavy for its size. The casing was green with verdigris, ancient and neglected, but the glass face was uncracked. Etched into the brass were symbols that made her eyes water if she focused on them too long.
"Antique," Miller said, peering over her shoulder. "Pawn shop loot? Probably dropped it when they ran."
Harlow held the compass flat in her palm. The needle didn't point North. It spun. It whipped around wildly, vibrating against the pin, before locking hard to the right—pointing directly at a solid brick wall.
"Compass is broken," Miller said.
"It's working perfectly ." Harlow stared at the wall. The mortar was crumbling , but the bricks looked solid. Yet, the needle insisted. *Here. Here. Here.*
She remembered the file on her desk. The rumors of the 'Veil Market'. A place that moved with the moon. A place where the city's impossible commerce took place. Morris had tracked it for months before he bled out in an alleyway with no shooter in sight.
"Stand back," Harlow ordered.
"Guv, it's a wall. Unless you're planning to headbutt it, I don't see what—"
Harlow raised her hand to the brickwork. She didn't touch it. She hovered her palm an inch away. Heat radiated from the cold stone. A hum, low and vibrating, traveled up her arm, settling in her teeth.
"Someone was here," she whispered. "Tonight. And they left this behind." She pocketed the compass . "We need forensics on the fluid. And get a team to scan this wall for voids."
"Voids? You think there's a room behind there?"
"I think there's a whole bloody station behind there that isn't on the maps." Harlow turned, her boot crunching on something brittle .
She looked down.
Glass. Broken spectacles. Round frames.
She crouched again, picking up the twisted metal. A fragment of a lens remained. There was a smear of blood on the rim.
"Miller, bag this. Separately. Fast track DNA."
"Who do you think it belongs to?"
"A witness," Harlow said, her mind flashing to the dossier of associates connected to the clique she'd been tracking. A redhead. *Eva Kowalski *. Researcher. "Or a victim."
A sound echoed from the tunnel deeper in—the direction the compass needle had ignored.
*Scritch. Scritch. Drag.*
Miller spun around, hand going to his baton. "Hello? Police! Show yourself!"
The sound stopped.
"Miller," Harlow said, her voice dropping to a command frequency that brooked no argument. "Don't move."
"It's just a squatter, Guv."
"Light off. Now."
"What?"
"Kill the light!"
Harlow killed her torch, plunging them into absolute, suffocating darkness. The afterimage of the flashlight beam burned in her retinas.
In the silence , the sound returned. Closer. It wasn't footsteps . It sounded like dry leaves skittering over pavement, or sandpaper on bone.
*Scritch. Scritch.*
"I don't like this," Miller whispered, his breath shallow .
"Quiet." Harlow’s hand drifted to her side, finding the reassurance of her holster, though she suspected lead created in a factory would do little good here.
She watched the darkness. Gradually, her eyes adjusted, aided by the faint, impossible luminescence of the sludge pool ten meters back.
A shadow detached itself from the ceiling.
It was darker than the surrounding gloom , a tear in the fabric of the tunnel. It was roughly humanoid but elongated, its limbs possessing too many joints. It hung upside down, clinging to the vaulted bricks like a bat.
Miller shifted his weight . His boot squeaked.
The shadow's head snapped toward them. Two pinpricks of white light flared where eyes should have been.
"Run," Harlow promised the darkness more than she commanded her partner.
The creature dropped. It didn't fall; it flowed, hitting the floor with the sound of a wet sack and rising instantly, spikes of solidified darkness erupting from its shoulders.
"Miller, move!" Harlow roared, snapping her torch back on and aiming it directly at the thing's face.
The beam hit the creature and it shrieked—a sound of tearing metal. It recoiled, smoke rising from its skin where the photons hit.
Harlow grabbed Miller by the collar of his stab vest and shoved him toward the exit. "Go! Up the ladder! Now!"
Miller didn't argue. He scrambled back, boots slipping on the grime.
Harlow walked backward, keeping the beam trained on the entity. It hissed, pacing just beyond the circle of light, testing the edges. It was herding her. Not away from the exit, but way from the wall the compass had pointed to .
It was guarding the breach.
"We need backup!" Miller shouted from deeper up the tunnel.
"We need a priest," Harlow grit out. The thing lunged. Harlow fired—not her gun, but the torch, narrowing the beam to its highest intensity . She swept it across the creature's legs.
The shadow severed. The legs dissolved into smoke, reforming seconds later, but the delay bought her five yards.
She reached the iron rungs of the maintenance shaft. Miller was already halfway up, panting, radioing for help that wouldn't understand what they were hearing .
Harlow Holstered the torch, grabbed the cold iron, and began to climb, the shrieks below morphing into a guttural, mocking laughter that sounded suspiciously like Morris's voice.
She didn't look down. She looked up, at the grate showing the orange glow of London's streetlamps.
*They left a guard dog,* she thought, her heart hammering military time against her ribs. *Which means they left something worth protecting.*
A claw raked against the metal rungs just inches below her boot. Harlow vaulted the last three feet, tucking and rolling onto the damp pavement of the alleyway surface, kicking the grate shut behind her.
She slammed her body weight onto the iron cover just as something slammed into it from below, making the heavy metal jump.
Miller was staring at her, pale as a sheet, radio dangling from his hand. "What... what was that? A bear? A freak in a costume?"
Harlow stood up, brushing the tunnel filth from her knees. She felt the compass vibrating in her pocket, hot against her hip. She looked at the blood-smeared glasses in the evidence bag Miller clutched.
"That," Harlow said, watching the grate settle, "was a lead."