‘How do you want to do this?’ asked Nightingale.

‘You’re the expert, sir,’ I said.

‘I looked into the literature on this,’ said Nightingale, ‘and it wasn’t very helpful.’

‘There’s a literature about this?’

‘You’d be amazed, Constable, about what there’s a literature on.’

‘We have two options,’ I said. ‘One of us leads him around the crime scene, or we let him go and see where he goes.’

‘I believe we should do it in that order,’ said Nightingale.

‘You think a directed first pass will make a better control?’ I asked.

‘No,’ said Nightingale, ‘but if we let him off the lead and he runs away, that’s the end of it. I’ll take him for his walk. You stay by the church and keep an eye out.’

He didn’t say what I should keep an eye out for, but I had a shrewd idea that I knew already. Just as I’d suspected as soon as Nightingale and Toby vanished around the side of the covered market. I heard someone pssting me. I turned around and found Nicholas Wall-penny beckoning me from behind one of the pillars.

‘Over here, squire,’ hissed Nicholas. ‘Before he comes back.’ He drew me behind the pillar where, among the shadows, Nicholas seemed more solid and less worrying. ‘Do you know what manner of man you’re keeping company with?’

‘You’re a ghost,’ I said.

‘Not myself,’ said Nicholas. ‘Him with the nice suit and the silver cad-walloper.’

‘Inspector Nightingale?’ I asked. ‘He’s my governor.’

‘Well, I don’t want to tell you your business,’ said Nicholas. ‘But I’d find myself another governor if I was you. Someone less touched.’

‘Touched by what?’ I asked.

‘Just you ask him about the year of his birth,’ said Nicholas.