I said it was and they asked if I’d been in contact with her since.

‘No,’ I said. ‘I didn’t want to land her in it.’

‘So you don’t know she boarded an American Airlines flight from New York last night,’ said Finula. ‘That can hardly be a coincidence now – can it?’

We agreed that it probably wasn’t, but it also wasn’t anything I’d done.

‘Tell me, officer,’ said Nightingale. ‘Which worries you the most – the idea that we have our own channels of communication with the Americans, or that we don’t?’

‘What worries us,’ said Finula, putting the emphasis on the plural, ‘is that as the agency charged with the defence of the realm we are only hearing about this now.’

‘We didn’t feel it was required,’ said Nightingale. ‘We rather thought you had your hands full, what with the Irish Republicans and the like. And there was a clear agreement in 1948 that magic and the demi-monde would remain our responsibility.’

‘That was half a century ago,’ said Finula. ‘In those days we didn’t officially exist and we took a man’s word that he was playing a straight bat. Now we run recruitment ads in the Guardian and have a mission statement and everything. Things have moved on a bit, the world has changed and we with it – you have not.’ She glanced at me. ‘Or at least not noticeably. We cannot ignore the potential damage that could be inflicted by an individual armed with your suite of capabilities.’

I squirrelled away that last phrase for my upcoming briefing document.

‘Especially,’ said Finula, ‘when we don’t have an effective counter.’

‘Shoot them in the head with a rifle,’ said Nightingale. ‘Or a pistol from close range if the practitioner is not on guard.’

‘Would that work on you?’ asked Finula.

‘It has worked on me,’ said Nightingale. ‘Twice. You see, you can train an irregular in a couple of weeks and you can learn how to make a bomb by reading a book. But it takes years to become even somewhat useful in a fight using magic.’ He nodded in my direction. ‘Unless you’re a particularly gifted student and even then . . .’ he shrugged.

‘And its use in interrogation is limited,’ I said. ‘Because training someone to resist the glamour is easy.’

‘All of this is beside the point,’ said Nightingale. ‘We shall of course include you in the latest round of consultation papers, given that you are—’ he looked to me for help.

‘Stakeholders,’ I said and he gave me the ghost of a wink.

‘But unless you have anything useful to tell us, then I’m afraid you’ll have to excuse us,’ said Nightingale and stood. I dutifully followed him up.

They didn’t have anything useful to say after that, so we took ourselves off.

‘Another feint by Tyburn, do you think?’ asked Nightingale as we drove back to Belgravia.