‘A man in Clapham walked to his lock-up in his nightclothes, let himself in and drank a litre of antifreeze. It was treated as suicide, but the man’s husband told Donato he’d been sleepwalking a lot in the lead-up to the event. Then there was a young actor who lay down on a railway line – everything to live for, she’d just landed a role in a new series. We checked it out and she was a serial sleep-app abuser and had a system of alerts set up to stop her sleepwalking, but they’d been deactivated that night. We investigated a couple of drownings in the Thames, too, where the sleeping person appeared to have climbed over a rail or just stepped off the bank into deep water and didn’t wake up. Charlie, are you OK?’

I’ve choked on my coffee. I have a coughing fit and need to wipe my eyes. Roman hands me a napkin, watching me closely.

‘I’m fine,’ I rasp, waving him away. Sleepwalkers stepping into deep water. It’s my dream come to life. But how . . . ? I say, ‘Go on.’

‘The trouble with this is that it’s impossible to prove they were asleep without witnesses, and so far the closest thing to a witness that we have is you, Charlie.’

‘So . . . are you police, or are you not police?’ Shandy can be very persistent.

‘We are consultants to the police. We work in tech-based emergent crime. Sleep crime is a new area and there aren’t a lot of funds about, but both Donato and I have experience in more conventional cybersecurity. The murderer – or murderers – here are going to be very difficult to identify, and of course impossible to prosecute. Even if we knew who it was, we wouldn’t be able to stop them. The best we can hope for is to work out how the killings are being done, to devise protections. It will be some time before the law catches up to everything that can go wrong with BigSky.’

Shandy is openly baiting him. ‘I’ve heard BigSky is funded by crime syndicates.’

There’s an edge in his voice. ‘Who told you that?’

‘Can’t remember.’ Of course it was O, who was one of the original funders for BigSky back in the day.

‘Hmm. Well, the potted history of BigSky is that it was an anonymous start-up and purely crowdfunded on anarchic principles.’

‘Yeah, that never ends badly.’ Shandy snorts. He ignores her.

‘The whole idea was to get away from corporate greed and government bureaucracy, and for a while they did. But the bigger the organisation became and the more influential they got, the more opportunities arose for anyone with money to buy an anonymous stake and potentially leverage control in the direction they chose. So you could say BigSky have become a victim of their own success. But even if there is criminal money buried in there somewhere—’