‘And if the Real IRA hadn’t got that Special Branch inspector’s phone, the operation could have gone ahead and a lot of people could have died. What was going through their minds, Charlie? Don’t they know we’re on the same side?’

‘I’m assuming that if the undercover agent hadn’t been blown they’d have ambushed the bomb along the way. The SAS were ready and waiting.’

‘Again, if the Sass were there, why weren’t we told?’

‘We’ve no direct link with the SAS, Spider. That would go through the Cabinet Office in London.’

‘So no one had the big picture, is that what you’re saying? If that’s the case, it’s no wonder that things go wrong.’

‘It’s complicated,’ said Button.

Shepherd smiled thinly. ‘Yeah, that’s what I say to Liam whenever he asks me a difficult question. Complicated or not, what happened yesterday was a major fuck-up, if you’ll pardon my French.’

‘I can understand how angry you are.’

‘Can you, Charlie? When was the last time you shot two people? I shot them because it was the only option I had, but if it had been handled differently we could have taken them alive.’

Button nodded but didn’t say anything.

‘Answer me this, Charlie. MI5 and the Northern Irish cops are both after the dissidents, right? So why don’t they share intel? Why don’t they talk to each other?’

‘It’s a question of trust, or the lack of it,’ said Button. ‘It goes back to the 1998 Omagh bombing. MI5 had pretty good intel that there was a major bomb planned for Omagh or Londonderry but didn’t inform the RUC and twenty-nine people died. And even before then there was the alleged involvement in shoot-to-kill cases.’

‘Alleged?’ said Shepherd. ‘Didn’t Sir John Stevens say in his report that they’d helped the UDA in fifteen murders and been involved in fourteen attempted killings and sixty-two murder conspiracies?’

‘You and your trick memory,’ said Button. ‘Anyway, we’re talking about water under the bridge. Their murderers are all back on the streets, so it’s no use now bitching about what MI5 might or might not have done back in the day. But trust is a two-way street, Spider. And MI5 have plenty of reasons not to trust the PSNI. Back in 2002 the Provos broke into PSNI headquarters at Castlereagh and stole a stack of files. The Chilcott review looked at the break-in and recommended that MI5’s role in Northern Ireland be expanded. The PSNI weren’t happy, of course, especially when word went around that MI5 itself was behind the break-in.’

‘Any truth in that rumour?’

Button chuckled. ‘You don’t really expect me to answer that,’ she said.

‘Dark forces,’ said Shepherd.