AI The suspect's boot caught a puddle and kicked a fan of black water across the pavement. Quinn matched the stride, her lungs burning, the worn leather watch slapping against her wrist with every pump of her arms.
He'd bolted the moment she'd stepped through the green neon glow outside the Raven's Nest. No words exchanged. No warrant flashed. Just eye contact, a flicker of recognition, and then Herrera was gone , threading between Friday-night crowds on Old Compton Street like a man who'd practised this route before.
"Metropolitan Police! Move!"
Bodies parted. Not fast enough. A woman with shopping bags stumbled sideways and Quinn caught her shoulder, steadied her without breaking pace, lost half a second. Herrera hung a left onto Charing Cross Road and she followed, shoes slapping wet concrete, the rain needling her face and blurring the streetlights into smeared orange halos.
He was fast. Younger by twelve years, and he moved with the economy of someone who understood how bodies worked, which muscles to fire and when. She'd read his file. Former paramedic, lost his licence under circumstances that reeked of something the Met couldn't categorise. The scar on his left forearm had come from a knife attack in Whitechapel, but the incident report read like someone had redacted it with a flamethrower.
She keyed her radio without slowing. "Control, this is Quinn. Pursuing suspect on foot northbound Charing Cross Road. Male, late twenties, olive complexion, dark curly hair. Heading toward, toward..."
He cut right. Down a side street she didn't have a name for.
"Heading east off Charing Cross. I need units on the parallel streets, now."
Static. Then a bored voice: "Copy, Detective. Dispatching."
They wouldn't arrive in time. She knew it. They knew it.
The side street narrowed into an alley that smelled of grease and old cardboard. A restaurant's extraction fan roared overhead, pumping hot air that hit her like a wall. Herrera's silhouette flickered at the far end, and then he dropped. Not fell. Dropped. As if the ground had swallowed him.
Quinn reached the spot fifteen seconds later, chest heaving. A service hatch in the pavement sat open, its iron cover pushed aside. A ladder descended into orange-tinged darkness. She could hear his footsteps below, rapid but controlled, already fading.
She pulled her torch from her belt and pointed it down. Old brickwork. Victorian, from the look of it. A utility tunnel, or maybe an access shaft to the Underground. The air rising from the opening tasted of damp stone and something else, something herbal and sharp, like sage mixed with copper.
Her radio crackled. "Quinn, units are five minutes out."
Five minutes. An eternity in a foot chase.
She holstered the radio and gripped the ladder.
The rungs were slick with condensation. She descended twelve feet, maybe fifteen, and her shoes hit a platform of cracked tiles. The tunnel stretched in both directions, but only one set of wet footprints led forward. She followed them, torch in her left hand, right hand resting on the holstered ASP baton at her hip.
The tunnel bent. Twisted. The walls changed from Victorian brick to something older, rougher, blocks of pale stone with chisel marks that looked hand-cut. Gas pipes ran along the ceiling, but they'd been dead for decades. The only light came from a string of mismatched bulbs, some bare filament, some modern LED, strung along a cable that someone had nailed into the mortar with no regard for building regulations or basic electrical safety.
The footsteps ahead had stopped.
Quinn slowed. Pressed her back against the wall. Listened.
Voices. Not one or two. Dozens. A low murmur of commerce, of haggling, of transactions conducted in whispers. And beneath it all, a hum that vibrated in her molars, a frequency that felt less heard than endured.
She rounded the final bend and stopped.
The abandoned Tube station opened before her like a cathedral's nave. The original platform tiles remained in places, cream and green, the station name long since scraped away. But the space had been transformed . Wooden stalls and canvas-draped tables lined both platforms. Lanterns hung from the arched ceiling on chains of varying length, casting pools of amber light that overlapped and competed. Hundreds of people moved between the stalls, though "people" felt generous for some of them. A woman with skin the colour and texture of birch bark examined a jar of something luminous. A man in a pin-striped suit haggled with a vendor whose eyes reflected the lantern light like a cat's.
The Veil Market. She'd heard the name in three separate case files over the past year, always as hearsay, always unconfirmed, always dismissed by her superiors with the particular brand of condescension reserved for theories that made the brass uncomfortable.
It was real. It was operating beneath Camden in an abandoned Tube station, and it was the single most flagrant violation of approximately every law she could think of.
Herrera was nowhere in sight.
Quinn pressed herself into the shadows of the entrance tunnel and assessed. No uniform. No backup. No jurisdiction that anyone here would recognise. The radio signal had died two bends ago. Her torch beam would mark her as an outsider the moment she stepped onto the platform.
She switched it off.
The crowd moved with the practised choreography of regulars. Everyone knew where they were going . Everyone belonged. She watched a transaction at the nearest stall: a teenage boy handed over what looked like a small bone, bleached and carved with symbols, and received in return a paper bag that he tucked inside his jacket with the reverence of a jewel thief.
Bone tokens. Entry currency. She'd seen one before, in an evidence bag from the Morris case. DS Morris, her partner, who'd followed a lead into a tunnel not unlike this one and never came back the same. The official report said cardiac event. The unofficial truth was that Morris had returned with white hair, aged thirty years in a single night, and couldn't remember his own daughter's name. He'd died in a care home eight months later, staring at a wall.
Quinn's hand found the rough edge of the wall beside her. The stone was warm. It shouldn't have been warm.
She could turn back. Climb the ladder. File the location, request a tactical team, do this by the book. In five minutes the units would arrive at the alley above. She could brief them, secure the entrance, call in specialist support from, from who? Who in the Metropolitan Police dealt with an underground market that sold things that glowed and hummed and smelled like burning sage ?
Nobody. That's who.
Herrera emerged from behind a stall thirty metres away. He'd pulled up the hood of his jacket, but the Saint Christopher medallion caught the lantern light and flashed gold against his chest. He spoke to a vendor, an old woman hunched over a table covered in small glass vials, and she handed him something wrapped in cloth. He checked it, nodded, tucked it inside his jacket.
Medical supplies. Off the books. That was his role, she knew, providing care for people the NHS couldn't, or wouldn't, treat. The question was what those people were and what they needed that required ingredients from a market that didn't exist.
He turned and scanned the crowd. His gaze swept past her position, paused, and returned.
Their eyes met across the platform.
Herrera didn't run this time. He stood still, the medallion rising and falling against his chest, and watched her with an expression she couldn't parse. Not fear. Not guilt. Something closer to calculation, or maybe pity.
He raised one hand, palm out. Stay.
Then he reached into his pocket and pulled out a small object. Even at this distance, she could see it: a bone token, twin to the one from Morris's evidence bag. He placed it on the edge of the nearest stall, deliberately , facing her direction, and stepped back.
An offering. Or a trap.
The crowd shifted around him and a group of four, tall, hooded, moving in lockstep, crossed between them. When they passed, Herrera was walking toward the far end of the platform, where a second tunnel gaped like an open mouth.
Quinn stared at the bone token sitting on the stall's edge. Thirty metres of open ground. No cover. No badge that meant anything down here. And on the other side of that token, answers about Morris, about the things that happened in the dark spaces beneath London, about every case file that ended with "insufficient evidence" because the evidence didn't fit any category the Met recognised.
She thought about Morris's daughter at the funeral. Nine years old. Asking why her dad didn't remember her.
Quinn stepped onto the platform.
The crowd parted around her with unsettling precision, not hostile, but aware, the way a school of fish makes room for something they haven't yet identified as predator or prey. The herbal smell intensified. Her skin prickled with static that had no source. A vendor to her left stopped mid-sentence and tracked her with eyes that had too many pupils.
She reached the stall. Picked up the bone token. It weighed almost nothing and radiated a faint warmth , like a pebble left in the sun.
The old woman behind the table looked up at her. Skin like crumpled paper. A smile with too many teeth.
"First time, love?"
"Where does that tunnel lead?"
"Depends on who's walking."
"I'm walking."
The old woman's smile widened. She reached beneath the table and produced a second bone token, darker than the first, almost brown, and pressed it into Quinn's other hand.
"Then you'll need two. One to go in." Her fingers, cold and dry, curled Quinn's hand shut. "One to come out."
The implication hung between them like smoke. Quinn pocketed both tokens and moved toward the far tunnel, where Herrera had vanished. The crowd sealed behind her. The lantern light thinned.
At the tunnel's mouth she paused. The darkness ahead breathed, a slow exhale of cold air that carried the faintest sound, rhythmic , almost mechanical , like a heartbeat amplified through stone.
Her hand found her baton. The bone tokens pressed against her thigh through her jacket pocket, one warm, one cold.
From somewhere deep inside the tunnel, Herrera's voice echoed back to her, stripped of everything but urgency.
"Quinn. You need to see this."