Everybody knew they had played a big part in what happened to Selena Jensen last year, and they had never been caught. The problem was proving it; if it was them, they were good at hiding it.

On her desktop was an unsent letter she had written to them, titled Please Stop. Into it she had poured everything she really felt about these attacks against her, everything she had nobody in her life to tell. She was so angry. Every blow they struck made her want to scream. But who would listen? Even if there was someone, she would have to convince them of the truth, prove she wasn’t overreacting. The thought of it made anxiety wring her chest like a wet washcloth. It was better not to bother anybody else and handle it herself.

She let the cursor hover over the letter and wondered if she had ever really intended to send it, or if simply typing it had convinced her she wielded some kind of power.

The video finished. Kat set the next one playing and turned the volume up.

Wesley had to admire the fact that it had taken over a month for them to force Kat into closing down her Twitter profile, suspending her Facebook, deleting her YouTube channel and abandoning Instagram. At first she had fought back, retweeting and mocking them to try and get some support. All it really did was attract more trolls, enough to shut down anybody who came to her defence.

The hardest part had been getting her banned from the official Doctor Backwash fan forums. Wesley had never seen the web series, but all of his favourite YouTubers considered it worse than cancer. In the end, they had targeted a few major players on the forum until they identified Kat as the common denominator and cut her loose.

The only part of her online presence left standing was her personal website, and they’d made the photographs so that they could nuke this last outpost from orbit.

‘Almost ready,’ said Luke, dragging an image into place.

She brought it on herself. Wesley couldn’t let himself forget it. Before the summer, Kat had given a presentation in media studies about misogyny on YouTube and toxic masculinity, calling out a local YouTuber named TrumourPixel who ran a gaming and pranks channel. Everybody at school watched and loved him – she was just too sensitive about his non-PC style of humour.

Wesley had sent TrumourPixel an email about it as soon as the class was over, and couldn’t believe it when he got a response. It turned out Luke and Justin had done the same thing. Did they want to team up to take her down? Wesley had jumped at the chance. While Tru talked about it on his livestreams and made an attack video against her, they had begun to plot together.

This was an opportunity to prove himself. He had to take it.

‘Is that the best picture to use?’ said Justin.

‘It doesn’t matter, blue balls.’

Her website was mainly used for updates on the video game Kat was making. The home page hosted a sort of biography and a video of her, chatting self-consciously into the lens. Luke deleted it all, dropped his chosen image into place, and attached the rest to an email.

He leaned back in his chair. ‘We’re ready to go.’

As soon as the video shuffled to the next in the playlist Kat tabbed to Twitter. Muscle memory. Oops . . . That person doesn’t exist! She could still lurk on her favourite feeds if she wanted, but the well was poisoned now. When the harassment aimed at her had splashed onto innocent people, she knew she had lost.

Innocent people. As if she deserved it.

After the summer, she thought it had all blown over.