The Chorley house was just the other side of Lane End, itself a village just the other side of High Wycombe which could, I suppose, be described as a small town just the other side of London. Since we’d managed to catch the M40 during a rare moment of decongestion we made it there in less than an hour, not counting the stop off at Marks and Spencer’s for snacks.

We’d checked the location on Google Earth, so unless there’d been some drastic landscaping in the last couple of years, the house had two L-shape wings and was situated just below the brow of a wooded hill that overlooked the valley and the motorway that snaked through it. It was reached by a private driveway that peeled off the main road and looped up through the woods – Martin Chorley certainly liked his privacy.

We stopped off at the entrance to the drive for a quick pre-arrival conference and the last of the Percy Pigs.

I didn’t want Caroline to come up to the house.

‘On the remote chance he is the Faceless Man,’ I said, ‘then he might know about you and your mum. Better if he doesn’t know we’re working together.’

‘You expect me to wait in the car?’ said Caroline

‘Actually, no. Because we’re going to park the car right outside,’ I said. ‘I thought you could wait in the pub we went past back there.’

‘Back there?’ said Caroline.

‘About five hundred metres,’ I said. ‘It looked like they did food.’

‘And you didn’t think to stop when we went past?’

‘I didn’t think of it until we got here,’ I said. ‘Look, we’ll drive you back down the road and come back.’

I expected a longer argument but Caroline gave me a look, put up her hands and said she’d walk.

‘Can you bag us a table for when we’re finished?’ I asked as she started back down the road – she didn’t answer.

‘And that was in aid of what, exactly?’ asked Guleed.

‘I don’t trust them,’ I said. ‘I don’t trust her or her mother. I couldn’t leave her rattling around the Folly and I definitely don’t want her getting first dibs on anything Christina has stashed at her dad’s house. Particularly if she had a copy of The Third Principia.’

‘You think Caroline’d try and steal it?’ asked Guleed.

‘Believe it,’ I said.

‘What does Nightingale think?’

‘Maybe he just likes having someone to talk shop with, but he seems a bit too trusting to me.’

‘Maybe he’s picked up some bad habits,’ said Guleed.

‘Yeah – who from?’

Guleed looked down the road to where, despite the curve, we could just see Caroline trudging back towards the village.

‘Is there some reason why we’re still standing here?’ she asked.