Line of Duty review: Things start with a bang, as ever

No TV writer is better than Jed Mercurio at constructing tension, that peculiar alchemy of cuts and music and shifts in power

After a couple of years off, Line of Duty is the latest in a season of much-anticipated BBC returns – Partridge, Fleabag – and it might be the most exciting. It also gives us the chance to ponder a conundrum. The series is widely and rightly acclaimed as one of the best police programmes Britain’s made, alive with tension and skulduggery and tortuous plots. Over four seasons its creator Jed Mercurio shaped a worryingly plausible universe, where coppers at every level are bent by organised crime, greed and sex. So why was last year’s Bodyguard, which had many similar elements – dodgy coppers, criminals, terrorists – so disappointing? After a lively start it succumbed to the weight of its own preposterousness, like an overfilled shopping bag that doesn’t quite make it home.

Based on the first episode of this new series, what’s clear is that compared to Bodyguard, where all the heroes had big signs painted on them from the start, Mercurio’s masterstroke in Line of Duty is that the stars of his AC-12 anti-corruption unit all began as losers. At the start of the first series, Steve Arnott (Martin Compston) had been implicated in the wrongful shooting of a terror suspect. Kate Fleming (Vicky McClure) was downtrodden by her desk work. Their boss Ted Hastings (Adrian Dunbar) was an ageing Ulster moralist in a world of slick ladder-climbers. They were dogged but decidedly unglamorous, fully aware that nobody likes a snitch and their work often looked like impeding the real job of the police. Burnished by success they are less sympathetic, although none is entirely happy: newly bearded Arnott struts around the office in his snooker-player waistcoats but swipes dating apps at night; Hastings is in a cloud of question marks. He is living in a cheap hotel he still can’t afford, browsing his divorce papers.

Things start with a bang, as ever. No TV writer is better than Mercurio at constructing tension, that peculiar alchemy of cuts and music and shifts in power. On its way to a disposal facility a consignment of seized drugs is ambushed by a gang, with fatal consequences for three of the four police escorts. (“Drug disposal facility”: not a bad nickname for the TV industry.) Fleming and Arnott suspect an insider but quickly run up against internal obstacles. Something is going on at the top. The gang’s balaclava-clad leader, played by the ever-excellent Stephen Graham, is a snarling, menacing small man, circling his deputy Lisa (Rochenda Sandall) like a shark, urging her to take drugs and questioning her loyalty. The junior staff at the station are cheaper to bribe, and bear the brunt of any investigation long before their bosses are exposed.

The first episode is constructed around a twist visible at a thousand yards but it doesn’t matter. The old rhythm section is as tight as ever, the leads completely at ease in their roles. McClure, in particular, gives Fleming depth with a look or a grunt. Plausibility is a spectrum; Bodyguard became ridiculous but Line of Duty stays just the right side, and as usual there is more plot in an hour than in whole series of other programmes. As well as being gripping entertainment, Line of Duty has become an effective examination of the relationship between the state and the individual. The shadowy government forces are elected; the organised crime gangs are fuelled by the drug trade. The police are there to save us from ourselves but can only do it if they are subjected to constant scrutiny. It’s exhausting work, policing the police.