‘Usually a bit stunned to start with,’ I said. ‘Then they either get angry, go into denial or just deal with it.’

‘Sounds familiar,’ said Dominic.

‘Unlike some rivers I could mention,’ said Beverley.

‘What else can you do?’ asked Dominic.

‘More importantly,’ said Beverley, ‘what makes you think this is going to work?’

‘Because incorporeal entities need power to interact with the real world. And this,’ I pointed at the werelight above me, ‘is the all-you-can-eat-buffet sign.’

‘You know that sounded completely mad, don’t you?’ asked Dominic.

‘Sorry,’ I said. ‘Professional hazard.’

‘Yeah, yeah,’ said Beverley. ‘Enough distractions. Let’s do it.’

So into the woods we went – it was surprisingly noisy. Especially one loud bird whose chirping sounded far too cheerful for the middle of the night.

‘That’s just a robin,’ said Beverley.

I said I thought they were diurnal.

‘All day, all night,’ she said. ‘They don’t shut up.’

Somewhere deeper into the gloom, amongst the straight trunks of the western hemlocks, something else made a sound like a ZX Spectrum loading a game off a cassette – Beverley said it was a nightjar.

Even without the sun, the air was warm and spiced with resin and the smell of dusty bark.

About fifty metres up the track it separated and we took the right-hand path which, according to my map, led us parallel to the top of the ridge. Because we were supposed to be looking out for anything weird we didn’t talk and in that strange stumbling silence I felt as if my senses had contracted down to the small flickering circle of the werelight.

After a quarter of an hour or so we reached a T-junction where the Mortimer Trail separated from the logging road.

‘I think this might have been a mistake,’ I said.

‘Definitely is,’ said Beverley, pointing to the left which was noticeably darker than the right. ‘Because we are not going up that way.’

‘No,’ I said, blinking to try and get my night vision back. ‘I mean the light – I should have used a darker point source.’ If only lux hadn’t been so reliable as a ghost attractor. I checked the cricket bat and saw that the LED had gone out. When I shook it next to my ear I could hear sand sloshing around inside. I swapped it for the next bat – the LED flickering as soon as I turned it on.

‘Left or right?’ asked Dominic.

I considered it. If the point was to attract things to us, then taking the easier road made sense. I’d have liked to take the right-hand trail to Croft Ambrey, but I wasn’t sure I wanted to be stumbling around an Iron Age fort, what with ditches and ramparts and other convenient limb-breaking opportunities, until I’d had a chance to suss it out in daylight.

This, by the way, is what we call in the trade a risk assessment.