These two girls were no different. What amazed her was the lack of privacy settings on their accounts. Anybody around the globe could access them and see their most intimate photos, captioned with laments of teenage loneliness and vulnerability.

Chloe Tate and Sasha Granger were typical fifteen-year-olds, but that meant different things to different people. In Kate’s day, as a fifteen-year-old, decades ago, the quintessential schoolgirl on the cusp of adulthood, raging with hormones, was likely to be found in the same dresses, covered in the same amount of make-up, displaying their desire to be noticed not on an international platform, but down the local pub, trying desperately to get served alcohol. Now the booze was irrelevant. There was a dealer on every park bench and at every school gate, and the attention came thick and fast into your inbox. The neighbourhood bar, with a few perverts hanging about, had turned into a gigantic international market, with no hours, no closing time, no taxi rank and no exit.

She’d trawled through countless images of the two girls advertising themselves as good time party players, ostensibly not caring about who might be watching. Each of their images garnered thousands of likes and messages from all over the world. It was par for the course nowadays that if the police suspected a crime, they could access private data by requesting it from the platform provider. Kate had already done that and discovered that the girls had had conversations with men much older than them, all interested in making a connection. It was a nightmare world which parents failed to regulate because they had no idea it went on. The networks themselves weren’t even obliged to watch over activity of minors. Trying to protect kids from crime was like shovelling snow when it was still snowing, and in the Lake District, Kate knew how hard that was. She could see outside against the street lamps that a heavy night of snowfall was ahead and it matched her mood.

Everybody thought it was easy to police this sort of thing, but it wasn’t; it was almost impossible. Looking at the profiles of the two girls was frankly depressing and a heavy feeling settled in her stomach. What had they got themselves into?

Now, she received a call from the mother of Chloe Tate. She sounded wary.

Kate explained who she was.

‘Chloe isn’t here,’ the mother said.

‘Do you know where she is?’ Kate asked.

‘Is she in trouble?’

‘No, there’s nothing to worry about. Her name has come up in an inquiry of ours, that’s all. We need to speak to her and her friend, Sasha. Do you know when she’s due home?’ Kate asked. She’d tried the girls’ mobile phones, which was perfectly legal, but they weren’t answering.