Cooper parked the Toyota across the Citroën’s tail end to block it in. As they approached the vehicle on either side, he spoke into his radio.

‘Diane, we’ve got Mullen’s car, in the main entrance to the shopping village. Right on the forecourt in front of the doors, you can’t miss it.’

‘You said that about Dinkie Donuts.’

‘Georgi and I are right here.’

‘Who’s in the car?’

Cooper peered in through the windows, though he’d already guessed the answer.

‘No one. They’ve legged it.’

‘Where could they have gone? The shopping village is closed.’

‘They can’t have gone far.’

Then Cooper saw an iron stairway leading down from the forecourt. At the bottom was a door into the second level of the car park, just below the road. The door was painted red and lit up like a beacon. And it was open.

‘That’s the obvious way, Georgi, wouldn’t you say? Especially if you were in a hurry.’

‘Let’s go, then.’

‘Hold on a minute.’ Cooper fetched his torch from the back seat of the Toyota. It was a four-cell Maglite, nearly fifteen inches long and weighing at least a couple of pounds. Not only would it give him a good light, but it was handy as a weapon, at a push. Then he found a spare torch from the car and handed it to Kotsev. ‘You might need this.’

He turned at the sound of a horn, and saw Fry’s Peugeot approaching, and her window winding down.

‘We’ll come in from the other direction,’ she called.

‘There’s a roof level up the ramp, Diane. You might start there.’

‘OK.’

She began to put her car into gear again, but Cooper put his hand on the door. ‘How far are we going with this?’ he said. ‘I mean, Brian Mullen hasn’t committed any crime that we know of.’

Fry gazed back coolly. ‘He’s running for a reason,’ she said, as the Peugeot pulled away.

Cooper and Kotsev clattered down the iron stairs and through the red door. Inside, the parking levels were already half empty, the gaps between vehicles allowing a view right down to the ramps at the entrance. They shone their torches into the corners and along the sides of the ramps.

They hadn’t been inside the car park long when Cooper heard a voice in his ear.

‘We’re coming in now,’ said Fry. ‘These attendants haven’t seen anyone in the last few minutes, but I’ll leave them to keep watch. How many parking levels are there, Ben?’

‘Three, I think.’

Cooper found a door by the stairs, which led into the main building.

‘Hey, there’s a door open here,’ he said.

‘Be careful, Ben.’

‘Aren’t I always?’

‘Actually, no.’

Cooper allowed himself a smile as he entered the darkened mill. The times Fry expressed concern for his welfare were so rare that they were worth collecting and treasuring for posterity.

He and Kotsev made their way slowly through the shopping floor. Although it was open-plan, there were far too many places to hide – counters and display units, racks of winter coats and free-standing shelves full of pottery. It would take dozens of people to search this place properly.

Without the presence of people, the dominant smell was the scent of polish rising from the wooden floors, as if they were walking through a low-lying mist. Cooper’s torchlight reflected off mirrors everywhere, dazzling him with sudden bursts of glare. Time and again, he caught a movement across the other side of the floor and swung his Maglite towards it, only to see himself or Georgi staring back from a full-length mirror, pale and wide-eyed like ghosts.

When they came to the central stairs, Kotsev gestured upwards, and Cooper nodded. He watched until Georgi reached the top of the first flight, then he moved on.

And it was better on his own, without the distraction of someone else’s footsteps behind him, another person’s breathing in his ear, or that continual jump and flutter on the edge of his vision. Now, he could concentrate on the natural sounds of the building, he could listen for the subtle intrusions into the silence, the surreptitious movement in the darkness.

When he felt the floorboards shift and groan under his feet, Cooper knew he was near the wooden steps that led down to the museum at river level. Standing perfectly still, he held his breath and listened. The faint creak of boards came from below him, somewhere near the bottom of the stairs.

The stairs led down to two doors, one opening into the spinning room and the other into the weaving shed. A doubling machine and some of the looms had been running last time he was here. The rattle of their bobbins and leather drive belts had seemed normal background noises then. Without them, the place was much too quiet, the long lines of wooden spindles dead and still, like rows of broken fingers.

His torchlight gleamed on white and pale blue walls, glared off red fire buckets, picked out the rainbow colours of the cotton on the bobbins. The weaving sheds had pitched roofs that were half glass to provide natural light for the weavers. Tonight, though, the glass only reflected his torch beam and the sporadic glint of machinery from the sheds beneath.

Cooper sniffed instinctively. The smell of lubricating oil and leather seemed stronger in the dark. Or perhaps in the silence. He wasn’t sure which made the most difference. His jacket whispered against the wall, every footstep squeaked on the boards. At this level, he could hear a deep rumbling noise, and even feel a faint vibration through the floor. Common sense told him it must be the turbines running. If they ran at night, they were probably supplying surplus power to the National Grid. But their rumble sounded more like the heart of the massive building, thudding through the walls of the mill, beating much too fast.

Cooper felt his own heart begin to thump faster in rhythm with the turbines, and his chest tightened with anxiety. It was as if he was picking up a sense of fear from the building itself. Be careful. Aren’t I always? Actually, no.

He froze to the spot, suddenly reluctant to go any further into the weaving shed. He didn’t know what he was afraid of. But that was always the most frightening thing, the unknown. You can onlyfear something that hasn’t happened yet. Damn right, Doctor. But lots of things had happened already. How many people had died? Too many to count.

For a moment, the rows of looms blurred and distorted. They seemed to change shape, mutating into crouching, angular beasts that lined a tunnel stretching away from him. They beckoned him further into the darkness, whispering with leathery tongues that had formed from their drive belts and pulleys.

Cooper shook his head, trying to drive away the illusion, to deny the lies that his senses were telling him. Then, at the far end of the weaving shed, he saw what his attention was being drawn to. His unsteady torchlight had picked out a shape on the floor. A bundle of rags, a pile of sacking? Well, it was possible in this place. Anything was possible. But Cooper knew it wasn’t a bundle of rags, or a pile of sacking, or even a trick of the light. It was a body.

‘Oh, shit.’

He recognized the smell of blood. This must have been the trigger for his anxiety, the message that his senses had been sending him. Blood meant danger. Be careful.

Suddenly, his surroundings came back into normal focus, and his feet began to move him forward again. Cautiously, Cooper edged around the looms and the other machines, checking the darkest corners of the shed, until he was bending over the body and feeling for a pulse. Despite the amount of blood matting the hair and spreading across the concrete floor, there were still signs of life.

There had been silence from his ear piece for several minutes now, and Cooper knew he’d lost contact. He pulled out his mobile, praying there’d be a signal. It wasn’t guaranteed, especially since he was below road level. But he was in luck for once. First he called for an ambulance, then he rang Fry’s number.