In the rearmost carriage on the train home, as far from other passengers as possible, I sat in a corner seat with the hoodie pulled over my head. I had nothing to do. Nothing to read, no one to talk to. Nothing to think about apart from police stations and DNA evidence and what I would say to my wife and child. My mobile phone, on the train table in front of me, was my only companion. And however much I tried to look out of the window as eastern England rolled by, my eyes were drawn back to the rectangle of black plastic time and again. It was my only connection to my family. My only weapon in the fight.

Except this weapon – or rather its predecessors – had already burned me twice. The first by its discovery in a suspicious place. Then by a suspicious internet search history stored in the memory of its replacement. Maybe this expensive piece of highly engineered electronics was ready to betray me for a third time. What else could it be hiding?

I opened up Google and went through the search history from the last couple of days. How did you even hack into that? The searches all looked familiar in any case: train timetables, maps, the solicitor’s number from Mel’s secret mobile, searches on Sunderland and casinos in the city centre. No surprises there. What else could it be? All the text messages looked familiar. The only image in memory was the naked selfie of Mel, and I couldn’t bear to look at that again. I put the mobile on the train table in front of me, turning it over so it was face down. The camera lens looked at me, reminding me of the webcam on our home PC, how it had been watching me on Sunday night.

Maybe it’s not what I’m doing, but what the phone’s doing.

The train was pulling out of Newark Northgate station. Maybe halfway home. We picked up speed and soon the outskirts of the market town were left behind, replaced with flat countryside ploughed brown for the coming winter.

I turned the phone face up again.

How are you going to betray me next time, you little bastard?

So much of our existence was on these things: networks of friends and colleagues, social media, email, apps, photos, music, work calendar, lists of birthdays. A download of our lives. There were a dozen or so apps in the memory. Back up, MyFiles, Diagnostics. Most of them were familiar: the usual default apps that were pre-installed when you got a new phone. Administrative apps that helped you manage your phone’s memory or move files around. The kind of thing I didn’t usually bother with.