Well, my goodness, here’s a thing: a reality show that feels real. I can’t remember the last time something felt real (including reality), but Banged Up strikes out against the tide. I suspect the makers would prefer their series in which celebrities do a week in the decommissioned HMP Shrewsbury with former inmates – instructed to behave exactly as they would have done while serving their sentences – to be referred to as a social experiment. But it is a reality show, albeit one with far less fake tan, no expensive breasts or dental work and with an air of genuine violence hanging over the whole. The opening episode introduces three of the seven celebrities who have volunteered for this odd experience. First up is Sid Owen, formerly Bianca’s Rickaaaaay! in EastEnders. He credits acting with saving him from ending up in prison like most of the men in his family. His dad has done time for armed robbery, one of his brothers for theft and another for drug trafficking. His mum was, he says, a petty thief. “We were poor but we didn’t want for anything because we’d just go out and nick it.” He seems to be there partly to understand his father and brothers better, partly to make up for not visiting them enough when he was little and scared of the place and partly to do some strange penance for his good fortune. He is cellmates with money launderer Reece McCoy, who tries to entertain the new boy with memories of prisoner scaldings with hot water and sugar. “His face was bubbling!” Then comes Tory MP Johnny Mercer, Sandhurst graduate and former member of the commandos who has come, he says, to gain insight into the system. He is paired with contract killer Kevin Lane who feels bad about the time he kidnapped, beat, gassed and nearly drowned the wrong man. Fortunately a passerby pulled his innocent victim out of the Thames and he lived. “I’m a nice person,” says Lane, “but I had no father to guide me.” It would be funny if there wasn’t an almost visible aura of mortal danger around him. A caption at the start of the programme assures us that all the ex-convicts involved served their time and are reformed. Looking at Lane, you have to hope this assurance is firmly backed by facts. It is fascinating to watch Mercer press him on the morality of his actions. Is it courage or the fat cushion of privilege around him that makes the MP feel untouchable? Finally, in this episode, there is former Gogglebox star Marcus Luther who believes that a criminal career is a choice. “I grew up in the hood,” he notes. “I chose to do the right thing. Not to do crimes.” He is there to try to gain experience that might help him guide the young men at his boxing club away from their own potential bad choices. Luther is immediately targeted by a gang who want to “G-check” him (gangster check – see how hard he is and whether he’s affiliated with a gang) by forcing him to add to the 20,000 or so prisoner-on-prisoner attacks that happen every year. He refuses. “I’m going to be a light in a dark place.” By the end of the second day, he is looking strained. “Prison will take all the goodness you have,” notes McCoy, “and manipulate it into something negative.” Banged Up’s greatest strength is the lie it gives to other prison-set documentaries. What passes for even the grittiest, most honest depiction of prison life stands revealed as a mere shadow of a thing. The threat of violence in Shrewsbury is everywhere and palpable. Another caption at the start may tell us there is security 24/7, but this is easily forgotten as you watch the pressure of being locked up with a hundred volatile men build, as verbal threats of rape and other violence bounce off the walls day and night, as the sheer physical strength of them as they fling chairs at walls and otherwise go off is endlessly apparent and suffocatingly oppressive. How any of them – or the wardens – survive seems increasingly impossible to fathom. And how we expect anyone to emerge from there anything other than markedly worse in every way – for themselves, for society, for the future – becomes a ridiculous thought. Perhaps by the end of the series this will even occur to Johnny Mercer, secure though he seems in his belief that everyone can rehabilitate themselves if they really want to. Banged Up aired on Channel 4 and is available to stream