‘Who’s this?’ asked Stan. She was dressed in a blue boiler suit with the top half undone and tied around her waist by the arms, and a grubby purple T-shirt with the OCP logo on it. If I’d met her while on patrol in London I’d have tagged her on general principles, but she wouldn’t have stood out. I realised that out here in the sticks I didn’t know what was normal. Maybe everybody dressed like that.

‘This is Peter,’ said Dominic. ‘He’s up from London.’

‘Oh, yeah?’ The words came out slowly, as if Stan was pissed and having to concentrate to speak clearly. I wondered just how badly she’d come off that bike.

‘Are you going to show us what you found, or what?’ asked Dominic.

Stan stared at me for a moment – her eyes were a pale grey and her right eyelid had a noticeable droop.

‘What about him?’ asked Stan.

‘Peter’s from the Met,’ said Dominic. ‘When he’s finished up here he’s going straight home. He’s not interested in any of your little crimes and misdemeanours.’

Stan’s head flopped forward as if it had suddenly got too heavy for her neck.

‘Okay,’ she said.

After about ten seconds of us all standing there like Muppets I looked at Dominic, who shrugged and indicated that we should wait. Half a minute later Stan’s head came up and, as if someone had wound her key a couple of times, she told us to follow her into the woods.

We trooped off behind her into waist-high bracken, down something that was not so much a path as a statistical variation in the density of the undergrowth. Despite the shade from the trees the air was warm and humid, and I was just thinking about taking my jacket off when Stan halted in front of a great wall of rhododendron bushes.

‘It’s in here,’ she said, before crouching down and crawling into a narrow gap. Reluctantly, I followed her into a short leafy tunnel that smelt like cheap air freshener, which opened up into a small clearing surrounded on three sides by more rhododendron bushes and on the fourth by a stumpy deciduous tree with shaggy leaves and branches that were so bent and twisted that its canopy brushed the ground. The clearing itself was an unusually regular rectangular shape as a result of being, I recognised, the foundation of a small building. At one end was a blackened fireplace defined by a circle of half bricks and large stones, and at the other a raised concrete plinth – a coal bunker or cesspit or something utilitarian like that. The cement floor had been exposed long enough for a couple of centimetres of powdery grey soil to build up on top.

‘Nobody can find this place,’ said Stan proudly.