Betrayal review – This pure ITV nonsense squanders an intriguing idea

Marriage breakdowns and cop dramas: two of the great staples of British telly. This psychological obsession with infidelity and espionage is, perhaps, a demonstration of the way in which the small screen offers a lurid portal into the unmentionable, secret sides of our buttoned-up national character. It also provides a roadmap for the new ITV four-part drama Betrayal, which combines these two genres to frustratingly mixed effect.

Shaun Evans is John, a British Intelligence operative with a reputation for doing things on his own terms. “We all know your gut is good,” Simone (Nikki Amuka-Bird), his handler at MI5, tells him, “but we have to prioritise using our resources carefully.” And so, John goes off on his own, resulting in him witnessing a brutal murder and being lined up for voluntary redundancy. But while he’s being squeezed out of the agency, he seems to have unearthed the credible threat of a mass casualty terror attack, possibly organised by the Iranian military. Teaming up with Mehreen (Zahra Ahmadi), a British-Iranian agent, gives John a last chance to salvage his career – but it might come at the cost of his strained marriage to Claire (Romola Garai). She is still reeling from a previous affair John had with a colleague, and as John and Mehreen get closer, John and Claire are pulled further apart.

Clearly, someone at ITV had the neat idea that you could construct a drama that pairs two types of betrayal. A criminal gang in Stockport, hired by an Iranian general (played by Omid Djalili), betray their country by surveilling, threatening and attempting to assassinate a dissident. Both John and Claire feel tempted to betray their marriage as the nature of their work and background (“sorry I’m not middle class like you!” Liverpudlian John rails) drives a wedge between them. And are there other treacheries lurking amid the agents and informers? Executing this premise is David Eldridge, an acclaimed playwright making his TV serial writing debut, which suggests a degree of ambition.

But there is something that happens the minute a writer starts work on a primetime ITV thriller. However intriguing the concept, however competent the assembled talent, the gravitational force of ITVness begins to assert itself. Betrayal starts with an interesting idea – a marriage drama masquerading as a spy thriller – but quickly reverts to something more familiar. “I don’t want to be responsible for missing a terrorist attack,” John implores his superiors. “Do you?” And so, he’s allowed to run around, a rogue but charismatic secret agent, bribing witnesses, bugging suspects, and having a shoot ‘em up in plain sight. The question of interpersonal betrayal becomes laced with a national security threat. Counterintuitively, the higher the stakes, the less interesting the betrayal. There have been sophisticated shows in this genre (Slow Horses, London Spy, even Black Doves) that treat their protagonists as real people, with real desires and fears. But Betrayal ultimately resolves that, in a 9pm primetime potboiler, emotion must serve to propel the plot.

Even if it’s not doing anything interesting, Evans is still a likeable lead. Familiar to audiences from his role as young Morse in Endeavour, he brings an obnoxiousness to John that is pleasingly unusual. Garai – one of Britain’s finest actors, and, last year, a two-time Olivier nominee – slightly phones it in as Claire but has enough innate quality to make their relationship plausible. Other performances are less convincing, and certain lines thud off the page. “John Hughes,” Mehreen announces on first meeting our hero. “Your reputation goes before you.” The geopolitically focused plot is, I suppose, slightly more novel than Line of Duty’s bent coppers or Trigger Point’s litany of improbably motivated domestic terrorists, but they all, ultimately, play out in the same way. The shock of violence, the draw of suspicion, the gut punch of deception.

The bods at ITV could have made Betrayal in their sleep. It is a well-honed formula, and it works: this four-part series will grip audiences for a week, keep them tuning in, and then be forgotten in time for the next show that comes along. It is the dramatic equivalent of a microwave dinner. Sustaining, but not nourishing. Even an intriguing, sophisticated idea – lasagna al forno – becomes edible, inoffensive mush under these demands. Betrayal might have been actively good, but, instead, it becomes defiantly okay.

‘Betrayal’ is on ITV1 and ITVX