As the screamer went flying into the undergrowth I shifted axis again, caught my ankle on something unseen and collapsed, flailing, into the bushes. Against my instincts, I stayed down, face pressed against the layer of decomposing leaves that Beverley assures me is a vital part of the arboreal ecosystem, and forced myself to take deep and regular breaths, even as random spores made my nose tickle.

There was wind in the treetops and I heard a vehicle go past, no more than twenty metres downhill – the main road. The trees around me were tall, with straight trunks supporting wide deciduous canopies . . . judging from the variation in colour and density there were at least two or three different species, not that I could identify them. Their lowest branches were too high up for me to climb and, apart from the bush I was lying behind, there was little ground cover.

I considered bolting for the road, but then what?

This wasn’t a unicorn I was dealing with. Martin Chorley wasn’t going to be stopped by any landscape feature short of a three metre concrete wall, and even then it would only slow him down for two, three seconds tops. Better, I decided, to rely on stealth – at least until I had a better idea of where he was.

‘Peter,’ said a voice far too close by. ‘This really is an exercise in futility.’

It sounded like Martin Chorley, only richer and with the timbre of confidence that posh people put on to convince themselves they know what they’re talking about. There was money in that voice, and breeding, and behind it all the mace, the whip and the bowler hat. I also didn’t think it was entirely natural.

‘I’ve done a deal with Lesley,’ said the voice. ‘I promised that no permanent harm will come to you.’ It seemed very close now – metres, spitting distance.

He had to know that I got a message out, and that it was only a matter of time before Nightingale descended on him in all his glory. Likewise he had to know that it was goodbye Faceless Man, hello plain old Martin Chorley, nominal and prime suspect.

‘Look Peter,’ said the voice. ‘I don’t have all day, so why don’t we get this over with?’

How not to be seen, lesson number one: Don’t stand up.

It started to rain, a persistent invisible drizzle that worked its way through the canopy and started soaking the back of my jacket and trousers. What with being overcast, it was beginning to get dark and I wondered who that would favour – me or him.

‘We both know the only reason you’re still alive,’ said Martin Chorley, a couple of centimetres from the back of my head, ‘is because I have a soft spot for Lesley May.’