jack.bick said the icon, and there was my avatar, email address and phone number. Quin selected me. He was not using any Tamesis interfaces that I recognised – I wouldn’t have been able to pull up any of this information. A bright yellow line appeared on the map, trailing down towards Liverpool Street, twisting about, then shooting off east, towards Mile End. My movements this evening. A squiggle in the streets above Mile End Road, around Pierce’s flat. A loop south of that, through the cemetery park. Another, dimmer line also snaked through the same streets – the walk I had taken with Pierce a couple of nights before.

Quin pinched his screen. We hurtled to a satellite’s eye view of the city, a faint veil of information passing behind the geographical overlay. And on top, my life: the yellow line, shuttling between Shoreditch and Pimlico, sweeping out to Barking, dangling down to Elephant and Castle. The line was annotated with pointers and dialogues, and intersections with other lines – my searches, information I had referred to, interactions with other users.

‘You’ve kept Tamesis online a lot lately, which is good,’ Quin said. ‘But as it happens, the software is pretty good at filling in blanks. Tube trips, for instance. When the Tube gets 4G that’ll be less of a problem. Other gaps. There’s a pub you like around here, on Whitecross Street.’

My mouth was open. Little could surprise me about Quin’s knowledge of my activities, but it was no less startling to see it flashed up on a cinema-sized screen.

‘Is there anyone you’d like to look at?’ Quin asked. ‘Your boss Eddie, for instance? Or … You had several recent interactions with another user …’

A search box popped up. K-a-y …

‘Stop,’ I said.

‘We keep these capabilities strictly private,’ Quin said, sensing my discomfort. ‘We didn’t build this system in order to spy on people. But the algorithm has to know all this stuff to do a good job, even if no one else does. This is just a party trick for investors. I didn’t show you when you came to interview me, did I? You got the kiddie tour. But you’re family now. Here’s your search history.’

Quin indexed through my most recent Tamesis enquiries. It was palpably violating, watching him scroll through my insecurities and typos. And he wasn’t idly browsing – he was looking for something.

He found it. Street crime overlays. Colour washed over London. Violent crime rates by ward; icons indicating individual incidents at particular times. We were not in the secret, all-knowing back room of Tamesis any more, this was the data I had seen when I asked about the best place to get mugged.