‘What about Clements’s point – the returnees from Syria? One of them could have the capability.’

‘But it still comes back to motive. Why would they?’ He clamped his hands together in front of him. ‘Since Seven/Seven, MI5 has been all about the Islamist threat. We’ve put so much effort into recruiting from the Muslim community, turning informers, the surveillance of would-be jihadis, there’s not been much left over for anything else. We’ve become obsessed with them. There’s a few of us who think we need to look elsewhere.’

Garvey guessed what was coming and launched a preemptive strike. ‘If this is about resources, forget it. We’re all running on empty, so don’t even think of asking.’

Woolf shook his head. ‘Elsewhere – by which I mean other disgruntled groups who are pissed off with the status quo and have a reason to make trouble and embarrass the government.’

‘Such as who? You’re not making sense.’

He reddened, but had no option other than to continue. ‘Your party’s in danger of losing the next election, but the opposition aren’t exactly electable, given their leadership. There’s a gap in the market, if you will.’

‘The far right’s become a disorganized joke.’

‘Exactly. But I’m not talking about a political party, more a groundswell of collective discontent. Which other groups out on the streets have reason to be disgruntled?’

She couldn’t see where this was going, but he didn’t seem to need prompting. She sat back and let him talk.

‘Former members of Her Majesty’s Armed Forces. In the last three years we’ve put another four thousand of them out of a job, one that most of them loved, that they thought was theirs for life. They view the withdrawal from Afghanistan very much as a retreat – they think we’ve thrown in the towel.’

‘Well, the government is committed to spending cuts. There’s no going back on that.’

‘They don’t see it that way. They feel their lives are being cut from under them. And they see we’re not winning the war on terror. And one thing they’ve all got in common – they’re trained to fight. Plus you’ve taken out a layer of police, who also didn’t expect to be looking for work. It’s a smaller number, but one that could be significant.’

She hadn’t heard this one before, though now he mentioned it, her inbox was full of complaints from ex-service constituents with one grievance or another.

Woolf took a breath. ‘The shooting: Halford’s in a hole because he knows it was a professional hit. And what he hasn’t told you is that they’ve confirmed the bullets were from a police firearm. But not one that was being carried by any of his team that night.’