We reached the Jag. ‘Can animals sense vestigia?’

‘It depends on the animal,’ said Nightingale.

‘What if it was one that we think might already be connected to the case?’ I asked.

‘Why are we drinking in your room?’ asked Lesley.

‘Because they won’t let me take the dog into the pub,’ I said.

Lesley, who was perched on my bed, reached down and scratched Toby behind the ears. The dog whimpered with pleasure and tried to bury its head in Lesley’s knee. ‘You should have told them it was a ghost-hunting dog,’ she said.

‘We’re not hunting for ghosts,’ I said. ‘We’re looking for traces of supernatural energy.’

‘Did he really say he was a wizard?’

I was really beginning to regret telling Lesley everything. ‘Yes,’ I said. ‘I saw him do a spell and everything.’

We were drinking bottles of Grolsch from a crate that Lesley had liberated from the station’s Christmas party and stashed behind a loose section of plasterboard in the kitchenette.

‘You remember that guy we arrested for assault last week?’

‘How could I forget.’ I’d been shoved into a wall during the struggle.

‘I think you hit your head much harder then you thought,’ she said.

‘It’s all real,’ I said. ‘Ghosts, magic, everything.’

‘Then why doesn’t everything seem different?’ she asked.

‘Because it was there in front of you all the time,’ I said. ‘Nothing’s changed, so why should you notice anything?’ I finished my bottle. ‘Duh!’

‘I thought you were a sceptic,’ said Lesley. ‘I thought you were scientific.’

She handed me a fresh bottle and I waved it at her.

‘Okay,’ I said. ‘You know my dad used to play jazz?’

‘’Course,’ said Lesley. ‘You introduced me once — remember? I thought he was nice.’

I tried not to wince at that and continued, ‘And you know jazz is about improvising on a melody?’