‘We’ve been through this. Many times.’ He glances up at Strover. She never raises something without a reason, doesn’t like to waste his time. ‘He doesn’t exist.’

‘But what if he does? A living, breathing person. And what if, nine years ago, he really did threaten Rob in Thailand, told him he would one day destroy him? I haven’t been able to stop thinking about it.’

The first turn of a knot begins to tighten in Silas’s stomach. He’s never heard Strover like this before, so animated.

‘Maybe Rob was terrified, took the threat seriously, wanted to do all he could to nullify it,’ she continues. ‘Wanted to be ready when Gilmour came looking for him. And to do that, to understand him better, he had to become more like Gilmour. Live like him in France. Break the rules. It’s then that he devised his ungodly plan, abducted the best super recognisers he could find in Europe, wired them up to live CCTV footage from airports and railways and shopping centres, and Centaur was born. But he didn’t develop Centaur for commercial reasons. It was for his own personal safety – an early warning system.’

‘What’s your friend in forensics found?’ Silas asks quietly, not sure if he wants to hear the answer.

‘I asked her to run a check on the desktop computer in Bex’s house,’ Strover says. ‘It was playing up at that party they threw for Kate. Jake said he’d been worried about it too.’

‘And?’

‘She found some malware on the hard drive,’ Strover says. ‘A remote access Trojan that hijacks the computer’s camera and microphone.’

‘Sounds like Rob,’ Silas says, relieved that Strover’s friend hasn’t unearthed anything else.

‘It was activated several times when Jake was staying there, when he was researching Rob. And at the party – a week after Rob died. It’s impossible to trace exactly where it was accessed from, it was routed through too many proxies, but she thinks the last time, at the party, the hacker might have been somewhere in South-East Asia.’

Thailand. Silas has a sudden urge for a cigarette.

‘There’s something else,’ Strover says.

‘Go on,’ Silas says, dreading what Strover might say next, how he’s going to break all this to his boss. Dinner with Mel is already looking unlikely.

‘Seems like Centaur came on-stream for a few hours on the day Rob was arrested, before the house in France was raided,’ Strover says.

‘Are you serious?’ Silas asks. The thought that any real data might have come via the brains of comatose people on a cliffside in Brittany is too sickening to contemplate.

‘No one was monitoring it,’ Strover continues. ‘My friend took a look this morning, out of curiosity. Decided to input Gilmour’s biometrics, based on the old Thai files. Just to see if anything came up.’

‘And?’

Strover pauses before she speaks. ‘It picked up a match.’