‘So long as it’s by text or email, yes. Let me know what you want to say and they’ll text it to Timber Wolf as if it’s from Gareth and make sure the answer comes to us, not him. They have a name for it, this technique, but I can’t remember it.’

‘But what about any real texts Gareth is sending or receiving?’

‘They’ll go through. The clever stuff is done on Timber Wolf’s phone. There may be some delay with his real messages while this exchange is on, but there often is anyway. He won’t notice anything unusual.’

‘He won’t think it’s odd that Gareth’s texting after they’ve been using WhatsApp?’

‘They use both. Their recent communications began with texts.’

‘I’ll need a briefing from you on the Brexit negotiations, everything you can find out about where they’ve got to and all that Timber Wolf has reported about them.’

‘When will you go?’

‘The sooner the better. It had better be a last-minute thing so far as Timber Wolf is concerned – Gareth must notionally be in Brussels unexpectedly and want to meet that day. If it’s not last-minute Timber Wolf has more time to go back with alternative arrangements, perhaps by WhatsApp, and then we’re scuppered.’

‘What if he can’t make it?’

‘He has to, even if it’s just a drink on his way home. Can you brief me tonight?’

That afternoon Shelley, Michael Dunton’s desk officer, asked Jenny for an appointment to brief Charles. ‘Tell her she can either hop across the river now or it will have to be some time next week.’

She arrived thirty minutes later, a fair, nervous-looking girl with a timid smile. Charles smilingly cut short her apologies for bothering him. ‘Don’t worry. The more favours I can do for Michael, the more I can ask in return. What exactly do you need from me?’

‘We want to do a clandestine search of his house, a breaking and entry operation. We’re doing the operational plan and Home Office warrant application at the moment. We’d do it of course when they’re out but it would help enormously if you and Mrs Thoroughgood were able to guarantee when that would be and for how long. You don’t know anything about their plans over the next two weeks, I suppose?’

‘Not at all. Of course, you know she works full time for the Department for Education so she’s fairly predictable, but he’s self-employed and is probably here, there and everywhere, depending on where the work is. But why d’you need to break in? It’s not just because of these knives?’