WARNING: CONTAINS SPOILERS

The first 45 minutes of White Bear, the second episode of Charlie Brooker's trilogy of technology-fearing dystopias, played out like a low-budget, low-quality version of 28 Days Later. It's basically the worst thing he's ever written, which, you come to realise, is the whole point.

A woman named Victoria wakes up from an apparent suicide attempt, unable to remember who she is. To make matters worse, the world outside makes no sense either: mysterious transmitters have turned most of the population into zombie-like voyeurs incapable of doing anything but filming her on their mobile phones, even as she's being chased by a masked gunman, screaming for help.

Lenora Crichlow as Victoria in 'White Bear'

Victoria soon teams up with Jem, a fellow 'survivor' who is neither affected by the radiowaves nor one of the 'hunters'. Together they embark on half an hour of horror movie clichés, narrowly escaping bad guys, being tricked into the woods where some Hostel-style torture is taking place and, finally, arriving with ludicrous ease to blow up the transmitter and save the day.

The whole thing is so hackneyed and formulaic, you're aghast. Has Brooker really gone this badly off the boil? Nothing about the plot lines or the behaviour of the characters is believable - except, that is, Victoria herself. You keep waiting for her to make the conventional transformation from scared witless victim to hardened heroine, but she doesn't. Lenora Crichlow, the actress playing her, just keeps crying and staring at the world in disbelief. It's a harrowing performance with no arc or resolutions, just sheer fear and distress.

What is revealed in the final act is that this is because Victoria actually is the only real character. The entire ordeal was a Truman Show-esque ruse made up of actors and set pieces. Suddenly finding herself in front of braying live audience, Victoria is told she abducted and murdered a child (which of course, she can't remember) and this - psychological torture and public humiliation - is her punishment. In a dreadful twist, she is then paraded through the street back to her house, where her memory is wiped and, like Prometheus, reanimated and forced to live through the whole nightmare again.

So the reason it all felt like a rubbish horror movie for 45 minutes is because that's what it was, just with a real person in the centre of it. Victoria's ordeal is exactly what a company of actors tasked with fulfilling a cruel society's fantasy of 'real justice' would come up with.

But how does that explain the voiceless hordes with the camera phones? It turns out they're White Bear's most important character, or least the one Brooker wishes to say the most about. They're members of the public, invited to watch and record Victoria's nightmare for fun. As in other episodes, Brooker is riffing on the idea that our compulsion to document our lives is replacing our desire to participate in it, like the people who see violence break out on a bus and decide to film it rather than intervene. The fact Victoria was a murderer allows them to accept her suffering, but it's the mobile phones that allow them to enjoy it - after all, she's just a character on their screens.

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