Byte-Sized Overview
Line of Duty is a British police corruption thriller about the awkward business of asking what happens when the police are the ones under suspicion. Set around the fictional Anti-Corruption Unit 12, the series follows DS Steve Arnott, DI Kate Fleming and Superintendent Ted Hastings as they investigate bent coppers, cover-ups and the kind of institutional rot that prefers a tidy filing system and a very selective memory. The hook is simple but mercilessly effective: every case is a maze, every interview is a trap, and nobody in the room is quite as trustworthy as they look.
What makes it worth your time is the way it turns procedure into suspense. Jed Mercurio’s scripts treat interviews as combat, paperwork as ammunition and a dropped detail as a future catastrophe. The show is also unusually good at making bureaucracy feel dangerous, which is not a sentence many dramas can proudly claim. If you like crisp plotting, clipped performances and slow-burn paranoia with the occasional jaw-dropper, this is the sort of telly that keeps making you say, “Oh, come on”, before immediately pressing next episode.
Transmission Details
- Show Title: Line of Duty
- Years: 2012-2021
- Created By: Jed Mercurio
- Network: BBC Two, BBC One
- Seasons: 6
- Episodes: 36
- Starring: Martin Compston, Vicky McClure, Adrian Dunbar
- Supporting Cast: Craig Parkinson, Keeley Hawes, Daniel Mays, Rochenda Sandall, Stephen Graham, Kelly Macdonald, Anna Maxwell Martin
- Genres: Crime drama, police procedural, thriller
- Status: Returning series; a seventh series has been officially confirmed, but it is not included in the released totals
Signal Strength
Line of Duty is at its strongest when it trusts the machinery of suspicion. Mercurio’s writing makes interrogation scenes feel like fencing matches, with each question built to expose another lie, or at least a better lie. The rhythm is brutally efficient: a clipped exchange, a meaningful pause, then a piece of information that changes the whole shape of the case. It is television that understands how far you can push a face before it becomes a confession.
The central trio is the show’s real engine. Martin Compston gives Steve a restless, battered sincerity that keeps the character human even when the story gets baroque. Vicky McClure’s Kate is tougher than she first appears, but never so hard that she stops reading as a working detective rather than a plot device in sensible shoes. Adrian Dunbar, meanwhile, turns Hastings into a glorious contradiction, all moral thunder and managerial chaos, a man who sounds like he could end corruption by sheer force of irritated grammar.
The series does lose momentum at points, usually when it gets too fond of twist-stacking for its own sake. Mercurio’s plotting can become so intricate that it risks feeling less like a conspiracy than a very aggressive spreadsheet. Some supporting storylines are given just enough room to be useful, then hurried away when the next revelation arrives. Even so, the show usually recovers because the performances are so alert and the direction is so committed to tension that even a wobble still feels purposeful. In less capable hands, the same material would collapse under its own cleverness. Here, it mostly swaggers.
Vibe Check
This is tense, talky, and extremely fond of making people sweat in fluorescent light. The pace is brisk without being breathless, though each series gradually tightens the screws until the whole thing feels like a pressure cooker with a warrant card. It is not action-heavy in the usual sense, but when violence arrives it lands harder because the show has earned the dread properly.
Fans of procedural drama will be very happy, though this is not a cosy “case of the week” watch. It rewards attention, punishes distraction and expects you to remember names, dates, alibis and the occasional suspiciously bland piece of administrative jargon. If you enjoy political thrillers, legal cat-and-mouse games, or dramas where a single interview can carry more menace than a car chase, this will be right up your street. If you want comfort television, look elsewhere and maybe bring a biscuit for moral support.
Spoiler Mode
The first series establishes the show’s core method: every investigation into serious crime threatens to become an investigation into the police themselves. Steve’s decision to challenge the official story around a shooting makes him an outsider inside the system almost immediately, while Kate is positioned as the sharp-eyed operative who can move between factions without fully belonging to any of them. The early arc also introduces the idea that corruption is rarely a lone wolf problem. It is usually a chain, and the show spends six series tugging at every link.
Series two pivots into the case of DI Lindsay Denton, a damaged, brilliant, maddeningly hard-to-read officer whose actions have consequences far beyond the immediate investigation. Keeley Hawes plays Denton as someone who seems to be perpetually one decision behind her own life, which is why the character works so well. She is neither saint nor cartoon villain, and the show thrives on the way she complicates every easy assumption about guilt. By the end, the story has widened into a much uglier picture of organised misconduct and the people willing to protect it.
Series three and four deepen the mythology of institutional corruption while shifting the show into bigger, messier territory. Dot Cottan’s role in the conspiracy reshapes the entire series, and Craig Parkinson makes him one of the show’s great slippery creations, a man whose expressions suggest he is always one polite sentence away from a lie. Later, the investigation into Major Anne-Marie McGillis, the criminal network around the OCG, and the rise of new internal threats push AC-12 into an increasingly unstable position. The show stops pretending there is a clean centre that can be reached if only the right people are brave enough. Instead, it argues that the corruption is distributed, adaptive and patient.
Series five and six are where the series becomes most obviously a national obsession. The story around Roz Huntley and later Jo Davidson turns the investigation into a meditation on how much evidence can be buried if enough people benefit from the silence. Stephen Graham’s John Corbett arrives like a grenade with a troubled past, and Rochenda Sandall gives Jo a guarded, wounded quality that keeps the later story from becoming pure mechanism. The eventual exposure of Ian Buckells as a major conduit is deliberately deflating in a way the show understands perfectly. The point is not that the biggest villain must be the most dramatic one, but that mediocrity is often what keeps corruption alive. By the end of the released run, AC-12 survives, but only just. Buckells is unmasked, Hastings’ position is weakened, Steve and Kate are left emotionally and professionally scarred, and the unit’s powers are visibly diminished. It feels less like a triumph than a temporary stay of execution, which is entirely in keeping with the series’ nasty little worldview.
Character Shout-Outs
Steve Arnott, played by Martin Compston is the show’s moral bruise, a detective who keeps trying to do the right thing while the job progressively teaches him how expensive that can be. Compston makes Steve quick, wary and slightly frayed around the edges, which is exactly what the series needs. He is not a superhero copper and never becomes one, which gives the audience a human anchor when the plot starts behaving like a corkboard attack.
Kate Fleming, played by Vicky McClure is the unit’s most quietly formidable presence. McClure plays her with precision rather than noise, which means Kate can listen harder than almost anyone in the room and still feel like the person controlling the room. She has to carry a lot of the show’s credibility, and she does it by seeming capable, emotionally intelligent and, crucially, not dazzled by anybody’s self-importance.
Ted Hastings, played by Adrian Dunbar gives the series its stern, oddball heartbeat. Dunbar makes Ted both authoritative and faintly absurd, which is a useful combination for a man tasked with policing other police officers. The performance lets the character be inspirational, compromised, pompous, funny and bruised, sometimes in the same scene. Ted’s speeches are half doctrine, half self-convincing ritual, and Dunbar sells every syllable.
Lindsay Denton, played by Keeley Hawes remains one of the series’ most memorable guest roles because Hawes refuses to make her simple. Denton is sharp, exhausted and often impossible, but Hawes keeps the character emotionally legible even when her choices become bleak. She brings a controlled desperation that changes the temperature of every scene she enters.
Dot Cottan, played by Craig Parkinson is the sort of character who makes deception feel like a full-time profession. Parkinson gives him the bland charm of a man who could vanish into any institution, which is why he is so effective as a conspirator. The performance is all restraint and tiny shifts, and that makes the later revelations land with extra force.
Jo Davidson, played by Kelly Macdonald adds a late-series layer of controlled unease. Macdonald keeps Jo guarded without turning her into a locked box, so the audience can feel the pressure of her situation without losing patience with her. She makes the character’s vulnerability and calculation coexist, which is no small feat in a show built on people hiding things.
Deep Dive Highlights
Line of Duty began on BBC Two before becoming a much bigger BBC One phenomenon, and that shift suits the show’s ambitions. It is made by World Productions and created by Jed Mercurio, who wrote all 36 released episodes, giving the series an unusually consistent voice across its run. That consistency matters because the drama is built less like a conventional episodic police series and more like a long-form pressure test. The plots are designed to accumulate, not reset.
The production moved from Birmingham for the first series to Belfast from the second series onwards, and that change gave the show a distinctly different visual identity. Belfast’s streets, offices and industrial spaces became part of the drama’s texture, even when the fictional setting remained deliberately unnamed. The locations help sell the show’s mood of institutional anonymity. This could be anywhere, which is exactly the point. The office spaces are clean but tense, the corridors are functional but inhospitable, and the streets have just enough grit to remind you this is not a glossy metropolitan fantasy.
The series is also notable for how it stages its interview scenes. Mercurio and the directors understand that a long take of people sitting under fluorescent lights can be more exciting than a car chase if the dialogue is precise enough. That is one of the show’s smartest creative bets. It turns ritual into suspense, and procedure into drama. The use of repeated formal spaces, the taped interviews, the evidence boards and the watchful office hierarchy all reinforce the sense that corruption is being fought inside the same system that keeps reproducing it.
Another key creative choice is the show’s refusal to make heroism tidy. Steve, Kate and Ted all make mistakes, backtrack, compromise or simply get outmanoeuvred. That gives the series a better sense of institutional realism than many prestige thrillers that mistake cynicism for depth. Here, cynicism is just the starting weather. The real interest lies in how people try, and often fail, to act decently within a rotten structure.
Legacy & Impact
Line of Duty is already one of the defining British thrillers of its era. It became a major ratings hit, especially after its move to BBC One, and it built the kind of cross-generational audience most dramas can only dream about while pretending they never wanted it. It also helped cement Jed Mercurio’s reputation as one of British television’s most reliable writers of high-tension, high-concept drama.
The show’s influence is visible in the way later British crime dramas have leaned harder into institutional mistrust, long-running conspiracies and forensic suspicion around police procedure. It also proved that a programme built largely from interviews, paperwork and moral anxiety could become a watercooler phenomenon. That is no small achievement. The series has also picked up major recognition along the way, including multiple Royal Television Society honours, which feels appropriate for something that made public service bureaucracy feel like an extreme sport.
Perhaps its biggest legacy is that it made viewers care deeply about a question that is usually reserved for cynical headlines: who watches the watchers? In Line of Duty, the answer is messy, compromised and never fully reassuring. Which, frankly, is why it works.
Skull Face’s Take
Line of Duty is must-watch television for anyone who likes tightly wound police drama, fastidious plotting and performances that can make a single look feel like a legal document. It is less suited to viewers who want neat resolutions, light-hearted banter or mysteries that behave themselves. The final run is strong, but the series as a whole is at its best when it is suspicious of everyone, including its own ability to surprise you.
Skull Face's Score
Skull Face's independent editorial rating
A superb, addictive corruption thriller with razor-sharp performances.
What works
- Outstanding central trio
- Electrifying interview scenes
- Long-form plotting with real bite
What may not
- Occasional overcomplication
- Some supporting threads are rushed