But then he thought, Come on, Drudgy. Come on, Count von Drudgenberg. You are not in ze kindergarten now. ‘Alright,’ he said. ‘It just seemed like everyone was busy for the time being.’

‘Of course they’re bloody busy. So ought you to be.’ Geraldine was staring at him as if at an exotic creature that might be a hoax. ‘You must be some kind of idiot savant,’ she said. ‘How you made that spot baffles me utterly.’

‘About that—’

‘You can forget the caveats now. Hasn’t anyone told you? It’s been verified. We’ve got another source.’

‘You’ve got what?’

‘Another source. In the Met. We’re on the line to him now. We haven’t told him about your spot yet but he says he’s been hearing things about a bombing, somewhere in central London, involving burqas. He’s been hearing about it today.’

‘Jesus,’ said Jeremy, his mind’s foundations swaying. ‘Really?’

‘Yes, really, you dolt. Pick up that handset and you’ll hear it.’

Jeremy picked the handset up off its cradle and put it to his flabbergasted head. Ben’s voice was saying, ‘…you been told about it?’

Another voice – a measured, careful voice – said, ‘The information’s been circulating in the department. I know that a number of my colleagues are currently looking into the situation and I’ll continue to liaise with them about how the investigations are progressing.’

‘Can you tell us what information you’ve got already?’

‘At present we’re working on confidential indications from our sources that, as I said before, there may be an attack planned within the next few days.’

‘By Atif Kayani and his gang?’

‘The identity of those involved is still the subject of police investigation.’

‘Sure, but if you were to, I don’t know, spot some terrorists scoping out a target in burqas, you would be reasonably confident it was Kayani?’

‘Hmm. It’s very difficult to comment on a hypothetical situation and, in any case, terror networks can be extensive and any individuals sighted, as in your example, might not be the primary members of a particular group. They frequently deploy secondary members for purposes such as reconnaissance. That’s been well documented. There’s a piece of research we’ve published in collaboration with King’s College London that should be useful to you, about hierarchies within terror groups. You can find it on their website, under “studies”.

‘But, essentially, if anyone were to be sighted, I would be reluctant to jump to over-hasty identification with particular suspects. After all, it’s a very difficult task, as I’m sure you can imagine, to correctly identify what are, ultimately, would-be criminals before they’ve committed a crime.’

‘So you’re saying that, even if you did spot some people, they might not be the ones actually planning the attack? They might just be hangers-on or something and the attack would actually be coming from someone else?’