‘Anything I can. Driving, ferrying goods and people about, that sort of thing.’

There was a pause. Charles could sense Sarah’s discomfort. He concentrated on Daniel. ‘Best thing you can do, Daniel, is to go home now and get it over with. It won’t take long and in a few days it’ll be history. Ring the house from here, say you’re on your way. Or we can do it for you.’

Daniel looked down at his boots again.

‘Be prepared for them to ask you about more than just the knives. They’ll probably ask about your friends and contacts, whether you know anyone with terrorist connections or extremist inclinations, that sort of thing. Again, play it straight and you’ve nothing to worry about.’

‘You mean they’ll try to get me to spy for them?’

‘They might but not necessarily. If they do – well, it’s up to you what you say. You don’t have to, there’s no compulsion, no coercion. Just be firm and polite. Always pays to be polite.’

‘But isn’t that what Prevent means? Penetrating Muslim communities and getting them to spy on each other? Getting teachers to spy on pupils?’

It was not the first time Charles had found himself having to defend, or at least account for, something in which he didn’t believe. Prevent was almost a misnomer, chosen for alliterative reasons to go with Protect, Prepare and Pursue as part of the wider counterterrorist CONTEST strategy. Never intended as a penetration operation, it was meant as a strategy to persuade vulnerable individuals away from violence or extremism by getting others in their communities to help. But making it a police responsibility like Pursue meant that many Muslims were reluctant to report friends or relatives for fear of arrest. Charles had argued that the attitudes needed to make it work had to arise from below, through day-to-day civic participation and trust in institutional fairness; anything enforced from above by official or officious interventions was likely to be counter-productive. Also not for the first time, he was grateful he was not running MI5 or the Met police.

‘No, it isn’t,’ he said. ‘We can talk about it another time if you like but it’s irrelevant in your case, anyway.’ He immediately regretted the phrase ‘your case’, with its implication that there might be a case to answer. ‘All you need do is tell the truth and answer their questions politely. If you don’t know something, just say so. And don’t go beyond their questions, don’t say more than necessary.’

‘The landline’s in the other room if you want to use it,’ said Sarah.

Daniel remained silent for a few seconds, then shook his head as if in response to an internal dialogue. ‘Thanks, I’ll go now. Thanks for your help.’