Line of Duty, Series 4 finale review - 'great acting, great writing'

Cop a load of that, then. Hana Reznikova is serving time for triple murder. Ted Hastings is on permanent gardening leave. The Huntleys have renewed their wedding vows on a family trip to Disneyworld. Just kidding. This is a Reg 15 alert to advise you that the following paragraphs contain almost nothing but spoilers.

So what happened in the dense, pulsating finale to series four of Line of Duty, its first on BBC One? “It’s complicated,” DCI Roz Huntley told her grouchy kids. It certainly was. Ever since her eyes pinged open at the end of episode one, we’ve been waiting for Huntley to navigate a path into a brick wall, and it eventually came to pass as AC-12’s implacable triumvirate bombarded her with forensic evidence incontrovertibly linking her to the death of Timothy Ifield. Did she have anything to say? She did, and it looked as if the weight of the world had been lifted from her shoulders as she explained that she had acted in self-defence, which she’d never be able to prove in court.

Even then Huntley had one last ace up her sleeve. Having first ascertained that she was still a police officer, she threw the book at pinstriped bruiser Jimmy Lakewell (the splendid Patrick Baladi, pictured right), whom she had cannily trapped into attending her interview as her solicitor, and then implicated him in the larger conspiracy. Lakewell, unflappable even as the cell door clanged shut, had the line of the night, which perhaps embodies everything we’ve ever seen in Line of Duty: "there are some people there’s no immunity from.”

The big question remains about Roz. Yes, like everyone else in this never-ending trawl through the cesspit of police corruptibility, she turned out to be a pawn in a much bigger game. But was her 11th-hour attack of conscience, in which she exculpated the father of her children, just part of her ongoing campaign to mimic the hallmarks of empathy? "I'm not a bad person" was her high old claim. Er, she had to be reminded that she framed two entirely innocent people and landed AC-12 in the soup to boot. She also tried to set up her own husband Nick (Lee Ingleby) as a murderer. Hats off to Thandie Newton (pictured below, before the amputation) for a riveting turn as a desperate moral nullity.

Other questions. Who’s Balaclava Man? More to the point, who isn’t? His identity was mostly a red herring: who instructed him, or them, turned out to be key. One of the links in the chain was ACC Derek Hilton - the real H? Paul Higgins (pictured below) skilfully suggested a weaselly, over-promoted corporate box-ticker whose conduct under pressure grew ever more shrill and erratic. One day, we may eventually find out who was controlling Dot Cottan, Tommy Hunter, Jimmy Lakewell, Derek Hilton, Lindsay Denton, old uncle Tom Cobleigh and all, and who keeps trying to bump off suspects and witnesses in transit (see also series two). "This is beginning to feel like a life’s work," said Hastings at the end. Good news for the viewer.

The confidence of Line of Duty is now at such a pitch that it can try anything and get away with it. After Lakewell called DS Arnott "Ironside", referring to another TV sleuth in a wheelchair, this episode flung in a left-field nod to Marion and Geoff (Nick Huntley was likened to Rob Brydon’s taxi-driving cuckold Keith Barret). Good to know DC Kate Fleming has fine taste in TV comedy. There were pop-up cameos for all comers. One of the DC-9 officers taking over the investigation from DC-12 was none other than Steve Arnott’s ex DS Sam Railston (Aiysha Hart), who could be conveniently guilt-tripped by Fleming into sharing crucial information. Guess it’s quite a small world in anti-corruption. One of the detectives interviewing Nick Huntley was CS Hargreaves (Tony Pitt) whose photo was one of the many adorning AC-12's wall of shame by the end. It should be noted that he's an H too.

This was a harum-scarum, high-octane finale that flew over every speed bump. Hastings summed up the bracing disregard for plausibility when he asked on behalf of us all if an experienced forensic investigator really couldn't tell the difference between unconscious and dead. And this is just a medical footnote, but do amputees spring out of bed with quite such freedom from constraint?

The episode was so rammed with thrilling plot that there was no time for DC Jodie Taylor (Claudia Jessie: great) to discover her boss/idol had deployed her as a swotty poodle to cover her tracks. Nor for Hana Reznikova to get out of jail. (Indeed, the young women at the heart of this whole sorry convulsion deserved more than Arnott's hasty wrap-up in the show's what-we-have-learned section.) Also, what exactly was the motive driving the pregnant PC Maneet Bindra (Maya Sondhi) to slip AC-12’s secrets to Hilton? What the hell was Balaclava Man doing turning up at AC-12 HQ? And why did it never occur to poor deluded DC Jamie Desford (Royce Pierreson) waving his gun around in the nailbiting finale that his computer had been hacked? We may wish to be told, but you can’t have everything on a platter.

The acting was great across the board because the writing was great: a synergy for which Jed Mercurio deserves every award, plaudit and slap on the back that comes his way. Line of Duty has entirely justified its exposure to the more mainstream audience on Sunday nights. As ever it was anchored by the three leads’ commitment to realism. Martin Compston as Arnott is so unactorly he sometimes contrives to sound like a speak-your-weight machine. Please can someone finally promote Vicky McClure’s Fleming? 

But this series has above all been a triumph for Adrian Dunbar as Hastings. With no fussy plotlines about a failing marriage or an on-off office romance to fill his dance card, he’s been allowed to focus on playing the wily old lion hunting the quarry he referred to as “the wee witch”. He's a nerveless marksman too. There was a wonderful moment as his hounds got another sniff. He stood at the glass wall of his office and looked out at them like a proud dad on the touchline, egging them on. For every viewer who has been gripped, that face said it all.

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