‘And if we can’t run him into his grave?’ I asked. ‘Do we have a plan B?’

‘Molly can do haemomancy,’ said Nightingale. ‘It’s very impressive.’

I sorted through my slim store of Greek. ‘Divination through the agency of blood?’

Nightingale chewed thoughtfully and swallowed. ‘Perhaps that’s not the best term for it,’ he said. ‘Molly can help you extend your sense of vestigia out some distance.’

‘How far out?’

‘Two to three miles,’ said Nightingale. ‘I only did it the once, so it’s hard to tell.’

‘What was it like?’

‘Like stepping into a world of ghosts,’ said Nightingale. ‘It may even be the world of ghosts for all I know. It might be possible to find Henry Pyke that way.’

‘Why can’t we do it that way now?’ I asked.

‘Because the odds are five to one against you surviving the experience,’ said Nightingale.

‘So, yeah,’ I said. ‘Probably best not to do it that way now, then.’

If my profession – that’s thief catcher, not wizard – could be said to have started anywhere in London, then it started in Bow Street with Henry Fielding, magistrate, satirical author and founder of what came to be known as the Bow Street Runners. His house was right next door to the Royal Opera House, back when it was just the Theatre Royal and Macklin was supplementing his gin-running activities with a bit of acting on the side. I know all this because Channel 4 did a TV drama about it starring the bloke who played the Emperor in the Star Wars films. When Henry Fielding died, his position as magistrate was taken by his blind younger brother John, who strengthened the Bow Street Runners further but evidently not to the point where they could stop Macklin beating Henry Pyke to death practically on their doorstep. No wonder Henry was pissed off. I know I would be.

It became London’s first true police station, and in the nineteenth century it moved across the road and became the Bow Street Magistrates Court – probably the most famous court in Britain after the Old Bailey. Oscar Wilde was sent down there for being a public nuisance, and William Joyce, Lord Haw Haw himself, started his short walk to the hangman’s noose from Bow Street. The Kray twins were remanded there for the murder of Jack ‘the Hat’ McVitie. It was sold in 2006 to a land magnate who turned it into a hotel because while history and tradition have a fine voice in London, money has a sweet siren song all its own.