The one that isn’t Becky is Melanie. Melanie has a line drawing of a face in the photo caption, all thick and twisty like the pen hasn’t been taken off the page. ‘Melanie Hasn’t Tweeted Yet’ but Melanie follows a few people – thirty-seven corporate accounts like BBC News, Sky News, Popbitch, and another dozen or so famous people, including a TV presenter who crossed the Gobi Desert on foot and whose dinner-party speciality is puffer fish. Then there are forty or so ‘ordinary people’, people who maybe said something funny once or do something unusual or are vocally for or against some issue or other. And she doesn’t check on anything they have to say, because all of them – the corporations, the celebrities, the nobodies – are padding to disguise the fact that Melanie is following Scott.

She knows it’s overkill, but Becky dreads the slip of a fingertip, an accidental ‘like’ or retweet of a Scott comment, anything that might tip him off that Becky Shawcross is monitoring him. Safer not to look directly at him.

Scott has changed his main picture again.

Now Scott is in fancy dress, dressed as Elvis in a maroon button-down shirt, the collar of a leather jacket pulled high around his neck and his hair styled like a whip of black treacle.

It’s not a picture she has seen before.

Perhaps he has been to a party.

She logs into Facebook, via another fake profile account. He friended her without asking questions. He already had 762 friends. Why not welcome another one? Somebody has tagged him at this party. Elvis lives! A grinning friend of his has slung an arm around Scott’s neck. Scott is pouting for the camera in aviators. Not for the first time, he has chosen a costume that allows him to wear sunglasses. He likes to hide his eyes, those giveaway windows to the soul.

She scrolls back through his timeline. She’s seen it all before, a thousand times. His whole life is in her head, or at least those parts that she can get at from the safety of her own flat.

Last year Scott purchased a large indoor fish tank. His colleagues appreciated the cupcakes he bought them one afternoon in Soho. He celebrated the birthday of his oldest house plant and 152 people put hearts by it.

Recently drank espresso Martinis with an old friend who’d flown over from Australia. You’d think he was Australian, with a name like Scott, but he’s English. Like Becky, he was brought up in Hounslow, where the roof tiles vibrate under the flight paths.