Rudyard Row was one of several narrow byways concealed among former industrial buildings in the centre of Crowley that were barely used in the twenty-first century. It didn’t lead to anywhere or from anywhere, and all the time she’d been a cop, Lucy had had no occasion on which to visit it. Even now that she was actively looking for it, she couldn’t go there by car, and so had to leave her Jimny on a backstreet in the vicinity of the Emporia.

From here, it was a ten-minute walk, first across the bus station and then downhill under one of the borough’s many railway bridges. At this point, she was already among shabbier retail units – charity shops, tattoo parlours and the like. With the town centre crowds falling behind her, she took a side street, formerly residential but now comprising two terraced rows of boarded-up shells, and at the end of that cut left along the towpath of the Bridgewater Canal. Fifty yards on, she turned right, walking down a cobbled alley which skirted around Trent & Son, a one-time cotton mill now ‘under redevelopment’, finally turning right again into the little-known defile that was Rudyard Row.

The first problem, which she only became aware of as she progressed along the Row, was how she was going to locate No. 38. Many of the buildings here were not just derelict, there were no numbers on their doors. It was nearly 2.30 in the afternoon, but the further along she travelled, the further back the hubbub of the town centre receded, and the more abandoned she felt this place was. Some of these aged, eerie structures were still occupied – she spotted an occasional light in an upper window, and fleetingly, from behind a half-open gate in a wall with barbed wire along the top, she heard the distorted cacophony of a too-loud radio, the sort of thing you heard when there were workmen on the premises. But even that diminished as she advanced, until, some fifty yards later, she couldn’t hear anything.

The only movement that caught her eye came when she passed a slice of sky between two tall buildings on her right, the lower section of which was bisected by the Archways, a Victorian-age viaduct carrying the Manchester-to-Southport railway. A blue-green, five-carriage caterpillar was currently trundling across it.

A few yards further on, she reached her destination.

The tell-tale numbers were no longer attached to the door, but there was sufficient scaly paintwork remaining to show the outlines where they had once been. The door itself had been damaged: one jamb, presumably where locks had once been fitted, had half-splintered from the wall, and it now hung ajar on a dingy, bare-looking interior.

Lucy pushed the door open.

In front of her, a three-legged stool lay on its side amid crumpled news pages. Beyond that, an uncarpeted stair rose out of sight, to the right of which a side passage led into pitch-blackness.