‘Are there any other ways of getting power, apart from making a sacrifice?’ Ross was using the tone she’d employ in an interview room, which was making Sefton smile.

‘You hear about people stealing power from others, or finding it or having it gifted to them, but those tend to be one-offs in specific circumstances.’

‘Okay,’ said Sefton, with a little look to Ross, who was now making notes at high speed. ‘You were talking about how things happen more easily in London if they’re talked about as being possible. Is that the start of London “remembering” something?’

Gaiman asked what exactly he meant by that, and Sefton tried to fill him in, without revealing operational details, about the conclusions his team had come to concerning, for example, the moment when Losley had been remembered by the metropolis and ghosts of her had appeared everywhere.

Gaiman finally nodded. ‘I didn’t know there was a name for it. But, yeah, when I’m here, I try not to talk about babies in microwaves. Try standing in Berkeley Square and reciting a poem about nightingales, over and over, for a day. My wife did that once.’ He found a picture of her doing so on his phone and showed it to them. ‘At the end, we were hearing their song, just faintly, but it was there. That’s a quaint feature. It can become pretty un-quaint. I think you might find that very important.’

Sefton was remembering their own terrifying adventures in Berkeley Square and could see that Ross had made the connection too. That wasn’t relevant right now.

Gaiman leaned forward. ‘There’s a question you want to ask me,’ he said, ‘but feel that you can’t, because it’d give too much away about what you’re investigating. So let me answer it anyway. No, I don’t think this Ripper of yours is a product of ostentation. He’s certainly been “remembered” by London, but—’

‘That’s confined to where it should be, in Whitechapel,’ said Ross.

She got one of Gaiman’s affirming nods too. ‘But I have been wondering if the sudden appearances of these flash mobs might be a product of ostentation. In London, tweeting about something might be planting the seed of that thing happening—’

‘So tweeting about a riot—’ said Sefton.

‘—could start one. If you knew how to do it just right. But also, imagine doing the opposite. What if you could seed the idea, especially right now, that everything was okay? That might start to make everything better.’ He smiled hugely.

‘Catching the Ripper would do exactly that,’ said Sefton.

‘It would,’ said Gaiman.

‘You seem,’ said Ross, ‘to be telling us a lot about what we need to do.’

‘Do I? Sorry.’