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 only fear 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.