James Graham is all over Oxford this term. His footballing love letter to Gareth Southgate, Dear England, whipped into the New Theatre in January, and now his 2017 docudramedy about Larry Lamb, Rupert Murdoch and the rising of The Sun in 1969 is the annual St John's College play.

Graham specialises in plays based on true events. And the key question of how to turn the vagaries of real life into apparently intentional drama is one to which he has clearly found the answer. More than that, it's the question that lies at the heart of this very play. Just as Graham the playwright sifts through the lives of his protagonists, forging a story like a sword-maker conjures pointed steel from lumps of dross, so Sun editor Lamb massages the facts for maximum popular appeal. Ink, as its title suggests, peers inside not just the newspaper industry, but at the art of writing itself. When Lamb tells Murdoch that there's no such thing as 'Why?' in a story, only 'What happens next?', he's scratching the itch in the playwright's own head. Do stories need to follow traditional narrative curves to succeed, or can they simply re-show events, as they happened?

St John's Drama Society also specialises in plays based on true events. They've been doing it for the last three years. First there was Frost / Nixon. Last year we had Enron. And now this. They're fixated on modern stories of power, politics and big business. Why? I bumped into Elspeth Rogers (director of the first two) outside the theatre, and she explained that the first was just a wild choice, and the second because she's always loved the play. Now, new director Georgina Cooper picked up the seeming policy of doing only recent-history-corporate dramas, and duly complied with Ink. Thus are Oxford traditions born, not out of coherent plans, but inherited coincidence.

At the heart of Ink are two powerful men: Rupert Murdoch and Larry Lamb. Murdoch bought the Sun from its parent paper the Mirror in 1969, when its circulation was at rock bottom, and hired Lamb to turn its fortunes around. In a fairytale-like challenge, he gave Lamb one year to overtake the Mirror’s circulation, and told him to do it by being as brash and populist as he dared. Over the course of the year, Lamb’s strategies became more and more bargain-basement as he scrabbled for every reader, and that graph on the wall inched ever higher. Would he beat the Mirror before the year was up?

As a premise, it gives the play a target to aim for. On the other hand, it’s hard to root for a central character as utterly devoid of morals as Lamb, or to side with a magnate as ruthless as Murdoch. The attraction of Ink lies not in any fellow-feeling with its protagonists, but a kind of horrified fascination at the depths to which they were prepared to stoop. Despite that, Rohan Joshi’s performance as Lamb builds impressively on his previous outings as Nixon and Skilling. He adopts a natural Yorkshire twang, and even finds genuine humanity beneath Lamb’s scurrilous exterior. There’s a core of resignation about the embattled editor, like a man hurtling to his death in a runaway train who decides the best he can do is sit in the driver’s seat and hold on. And despite his machinations, he’s honest. Even when, in his darkest moment, he asks Stephanie Rahn to pose nude as the first Page Three Stunnah, he does it without guile; just tragic, guilty honesty. That’s a complex character, and Joshi delivers with the charisma of natural talent.

St John’s has a proud tradition of including any of their students who wants to participate in their annual play, which means the standard of performance may vary, but the ensemble feels united. In this production, Joshi is carrying the lion’s share of the acting, and diction makes audibility an occasional problem with some of the actors. There’s nothing wrong with that – this is not an acting showcase. But if you can’t hear the words, it does make it hard to follow the details of what’s going on. In the first half especially, as Lamb recruits his team and gets pep-talks from Laurence Skinner’s Murdoch, it’s sometimes a struggle to keep up with developments. But Cooper’s direction is crisp, her lighting dynamic, and Dan Bleazard’s sets stylishly and simply evoke the restaurants and offices of 60s London.

Despite all this, the first half of Ink keeps the stakes fairly low. The Sun staff decide to run a TV listings page for the first time. They debate whether they should have a themed week about readers’ cats. It’s hardly edge-of-the-seat stuff. But it puts in place the ethical dilemma underpinning the show: was the Sun a new, vital beacon of populist media, or the moment serious journalism dumbed down and died?

In the second half, boy, do things get going. Mirroring the central theme of unpredictable incidents creating dramatic narratives, the stakes suddenly shoot up with two remarkable events, which turn Ink from a meandering meditation to a searing drama.

The first is the kidnapping of Muriel McKay, wife of Rupert Murdoch’s deputy Sir Alick McKay. Lamb decided to capitalise on his paper’s proximity to the figures in the story by publishing details of the affair that no other media could access, including letters from the kidnappers and even from Muriel herself, begging for rescue. The public ate it up. But Muriel ended up dead, and even Murdoch thought Lamb had gone too far. He had become a Faustus-like megalomaniac, toying with lives for his own ends, while an eternity in hell awaited. For the first time, the audience in Ink weren’t just amused. We were horrified.

The second incident is Lamb’s decision to put naked women in his paper. The scene where he calls the model, Stephanie Rahn, into his office, and tells her that he wants her to bare all so that he can overtake the Mirror’s circulation isn’t just an example of media immorality. It feels like a turning point in society. A moment from which none of us can turn back, and in which millions were complicit. A moment when we see a human being know they are doing the wrong thing, and decide to do it anyway. Like Juliet’s nurse saying ‘I think it best you marry with the County’, it takes away love, humanity and any remaining shred of decency in favour of material gain. The lights dim. The audience is trapped, silent, shocked. And the contemporary relevance overspills from the stage, as future echoes of Jeffrey Epstein and his powerful enablers ripple through Lamb’s sordid entreaty.

It’s the moment when he damns himself. And I was reminded of a piece of Ben Elton stand-up about Dante’s seven levels of hell. According to Elton, in the lowest level of hell stands Judas Iscariot, alone, repenting forever his betrayal of Jesus. But even lower than Judas, crouching between his legs, is the editor of the Sun, eternally peering up to see if he can tell people if Judas is gay.

Is Larry Lamb in the eighth level of hell? Or was he just doing his job? We’ll never know. Ink leaves us there, searching – as we were at the start – for meaning in a collection of events that just… happened. Maybe we should accept that there’s no guiding intelligence. Myths, like the St John’s Play, are created not out of planned structure, but random chaos. The sooner we accept that, the happier we'll be.