Run: 2026-02-24-01KJ8WHF9N05Q2B1QFV8MWS0B8

The entrance was a rusted service door set into a brick wall off Chalk Farm Road, sandwiched between a closed-down newsagent and a letting agency. Quinn found it propped open with a broken padlock, a uniform standing outside with his collar turned up against the October drizzle. "DS Brennan's already down there, ma'am." The uniform handed her a torch. "Mind the third step. It's gone." She descended into the dark. The staircase opened into a platform that the Tube maps had stopped acknowledging decades ago. Her torch swept across curved Victorian tiling, cream gone grey with age, and the remains of signage that had been stripped back to bare fixings. The air was cold in the particular way of underground spaces — still and damp and sealed against the world above. A generator hummed somewhere further along the tunnel. Somebody had strung portable work lights along the ceiling, and in their yellow wash Quinn counted four uniformed officers, a forensic technician crouched over an evidence bag, and DS Brennan standing with his hands in his pockets near the far end of the platform. He spotted her and lifted his chin in greeting. The body was face-down between the platform edge and the tiled wall, a man in his mid-forties, dressed in a long coat the colour of old blood. No wallet. No phone. The forensic technician had photographed the positioning before turning him, and Quinn studied the prints on her tablet as she crouched beside the remains. "Cardiac event," Brennan said, materialising at her shoulder. "Pre-existing condition, most likely. Came down here, had a turn, never came back up." "How did he get in?" "Door was already compromised. Rough sleepers use these places." Quinn looked at the man's hands. The nails were clean. The coat was expensive — she'd seen the label when the technician had pulled the collar back. A Savile Row cut, recently pressed. Not a rough sleeper. "Nothing on him to say who he is." "Not yet. We'll run his prints." She stood, her knees protesting the cold, and took a slow pass of the platform. The work lights threw hard shadows into every recess. At the mouth of the tunnel, where the track disappeared into black, she stopped. A woman sat on an overturned crate with a worn leather satchel in her lap, watching Quinn with green eyes behind round glasses. Red curls escaped from under a knit hat. She had the look of someone who had been told to stay put and was tolerating it with considerable effort. "Who authorised a civilian on my scene?" Brennan came up behind her. "Museum consultant. British Museum rang when we requested help identifying an artefact recovered near the body. She was apparently already on her way." "Already on her way," Quinn repeated. The redhead stood. "Eva Kowalski. I work in the restricted archives. Your forensic team found something and didn't know what they were looking at." She reached into her satchel and produced an evidence bag without being asked, as if she'd been holding it ready. "It's a navigational tool. Brass, eighteenth or nineteenth century. The engravings are protective in nature — apotropaic symbols, common in the period." Quinn took the bag. Even through the plastic the compass was striking. Small, no wider than her palm, the brass casing eaten green around the edges. The face was covered in fine-cut markings that ran between the cardinal points in a way that wasn't decorative. They were too precise for that, too intentional, each line intersecting in a logic that she couldn't follow but could feel at the edge of her comprehension, the way you felt grammar in a language you'd never studied. The needle sat still beneath its crystal face, pointing not toward the tunnel entrance — which was north — but toward a section of tiled wall beside the body. Quinn turned the compass in her hand. The needle held its position, indifferent to the rotation. "The needle's stuck," Brennan said. "Mechanism's corroded. We think it was the victim's — collector, maybe, or just someone who bought it off a market stall." Quinn looked at the wall the needle indicated. The tiles there were immaculate. She walked back toward the body and crouched again, this time ignoring the man entirely and pressing her torch close to the floor. The platform surface near the body was thick with decades of grime, disturbed in three places: the forensic team's boot prints, the body's own impression, and a third set, older than the team's marks but newer than the grime beneath, a pair of shoes with a distinctive narrow heel, already partially blurred by resettlement. "He wasn't alone when he came down." She followed the second set of prints with her torch beam. They moved from the body toward the tiled wall — and stopped. Stopped cleanly. No turn, no retreat. They simply ended. She stood and put her palm flat against the tiles where the footprints terminated. Solid. Cold. She pressed along the seam lines. "Detective." Kowalski's voice carried something careful in it, something that straddled the line between warning and information. Quinn looked at her. The woman's jaw was tight beneath her freckled skin. She had tucked a curl behind her left ear with a gesture that looked involuntary, a thing she'd done without deciding to. Her eyes moved from Quinn to the wall and back again, and in that flicker Quinn read what a woman with a master's degree from Oxford and access to restricted museum archives was choosing not to say. "You told me the needle was pointing to the wall." "The needle is stuck," Brennan said again. "You pointed the compass at several positions when you looked at it." Quinn held the bag up. "The needle hasn't moved from that wall since it came out of your satchel." Kowalski said nothing. Quinn turned back to the wall. The tiles were cream under the work lights, seamless, mute. But the second set of footprints ended in front of them as if the wall had simply accepted the person who'd made them. She pulled out her notebook and wrote down the compass's description. Brass. Verdigris. Sigils. Needle fixed on a single point. Then she drew a small sketch of the platform layout, marking the body's position and the arc of the second set of prints in relation to the wall. "Where was the compass found?" The forensic technician checked her notes. "Approximately thirty centimetres from the victim's right hand. Face-down." Face-down. Quinn looked at the original photograph again on her tablet. The compass had been placed face-down deliberately, or it had fallen from a pocket in a very specific way. Not from a pocket. A pocket would have sent it sliding toward the platform edge. It lay perpendicular to the body, away from it, as if it had been set down. Or dropped in haste. "He didn't own it," Quinn said. "It was left with him."