Line of Duty
Line of Duty is a British police procedural drama television series created, written, and produced by Jed Mercurio, focusing on the investigations conducted by the fictional Anti-Corruption Unit 12 (AC-12) within a metropolitan police force.[1] The programme follows detectives probing allegations of corruption, misconduct, and criminality among fellow officers, featuring intense interrogation sequences and narrative twists drawn from real-world policing inspirations such as the Jean Charles de Menezes case.[2] Premiering on BBC Two on 26 June 2012, it shifted to BBC One for later series and concluded after six seasons in May 2021, comprising 37 episodes produced by World Productions.[3] The lead cast includes Martin Compston as Detective Sergeant Steve Arnott, Vicky McClure as Detective Constable Kate Fleming (later Inspector), and Adrian Dunbar as Superintendent Ted Hastings, with recurring antagonists and guest stars highlighting institutional tensions.[4] The series garnered exceptional viewership, with its sixth-season finale attracting 12.8 million overnight viewers, later reaching 15.8 million including catch-up, marking it as one of the most-watched UK dramas of the 21st century and surpassing records set by prior hits.[5][6] It received widespread critical acclaim for its scripting, performances, and procedural authenticity, earning a 96% approval rating on Rotten Tomatoes across seasons and multiple BAFTA Television Award nominations, including wins for drama series and acting.[7] Defining characteristics include its unflinching portrayal of police internal accountability, eschewing sentimentality in favor of procedural rigor, which resonated amid public scrutiny of law enforcement but drew occasional critique for plot contrivances in resolutions.[8] No major production controversies marred its run, though its success prompted discussions on the sustainability of high-stakes TV formats reliant on escalating conspiracies.[9]Synopsis
Core Premise and Series Overview
Line of Duty is a British police procedural drama series created by Jed Mercurio, centering on the investigations conducted by AC-12, an elite anti-corruption unit embedded within a fictional regional police force tasked with rooting out internal misconduct among officers.[10] The unit's mandate involves scrutinizing allegations of corruption, ranging from procedural violations to more severe ethical breaches, often pitting its members against institutional resistance and the complexities of loyalty within law enforcement hierarchies.[4] Spanning six seasons broadcast from 2012 to 2021—initially on BBC Two starting 26 June 2012 and shifting to BBC One for later series—the program adopts a thriller format that foregrounds methodical evidence collection, covert surveillance, and intense interrogation sequences as AC-12 pursues leads on suspected wrongdoing.[10] Each season structures its narrative around standalone cases of potential police malfeasance, interconnected by recurring themes of accountability and the erosion of public trust in policing institutions.[4] Mercurio conceived the series to probe the dynamics of institutional corruption, emphasizing the tension between individual integrity and systemic pressures that enable ethical compromise, informed by broader observations of misconduct in public sector bodies rather than specific real-world scandals.[11] This approach underscores causal factors such as hierarchical cover-ups and the moral dilemmas confronting investigators who must challenge their own profession's norms to uphold justice.[12]Cast and Characters
Main Characters
The core protagonists of Line of Duty are the investigators of Anti-Corruption Unit 12 (AC-12), a specialized police squad dedicated to exposing internal corruption. Superintendent Ted Hastings leads AC-12 with authoritative diligence and a strong moral compass, overseeing operations that prioritize procedural integrity and the eradication of bent officers within the force.[13] His leadership style emphasizes relentless pursuit of evidence, often under intense institutional pressure.[14] Detective Sergeant Steve Arnott, previously a high-flying counter-terrorism officer, joins AC-12 after refusing to participate in a cover-up following the fatal shooting of an innocent civilian during an operation.[13] Arnott's principled stance and determination drive his investigative tenacity, making him a key field operative who challenges suspects directly and uncovers hidden networks of misconduct.[14] Detective Inspector Kate Fleming begins as a detective constable with expertise in undercover work, infiltrating target units like TO-20 to gather intelligence.[13] Ambitious and tenacious, her observational skills and adaptability provide AC-12 with covert advantages, evolving her role into a central strategic asset across investigations.[14] Season-specific antagonists include DCI Tony Gates in the first series, who heads the TO-20 serious crime unit with an exceptional clear-up rate and adoration from his team, yet faces AC-12 scrutiny amid suspicions of rule-bending influenced by personal stressors, such as his wife's departure with their daughters.[15] In the second series, DI Lindsay Denton, the sole surviving officer from an ambushed police convoy transporting a protected witness, is probed for orchestrating the operation that resulted in multiple officer deaths, revealing her professional competence layered with potential complicity in corruption.[16] These characters' professional backgrounds and traits underscore the series' exploration of moral ambiguity in policing, where high-stakes anti-corruption efforts expose tensions between institutional loyalty, personal ethics, and the compromises made to achieve operational successes.[13]Recurring and Guest Characters
Tommy Hunter, portrayed by Brian McCardie, serves as a foundational recurring antagonist across the first two series, embodying organized crime's strategic infiltration of law enforcement. Originating from Glasgow, Hunter led the nascent Organized Crime Group (OCG), engaging in activities including child exploitation rings and expanding influence through police informants; he entered witness protection as Alex Campbell after cooperating with authorities for immunity, only to be murdered in a 2012 ambush by subordinates suspecting betrayal.[17][18] His arc establishes the OCG's model of grooming vulnerable individuals for long-term placement as moles, perpetuating systemic vulnerabilities in policing.[19] Detective Sergeant Matthew "Dot" Cottan, played by Craig Parkinson, recurs in series 1–3 as a deeply embedded OCG operative posing as a legitimate officer. Recruited young through Hunter's network amid a disadvantaged upbringing, Cottan advanced to roles in witness protection and AC-12 itself, leaking intelligence and orchestrating diversions that shielded syndicate activities; his dying declaration in series 3—"The Caddy"—later exposes layers of complicity.[20][21] This character's trajectory underscores causal pathways of corruption, where early exploitation yields insiders capable of subverting anti-corruption units over decades.[22] Other recurring supporting figures include Detective Constable Nigel Morton, depicted by Neil Morrissey in series 1–3, who aids fraudulent schemes such as exaggerated injury claims for benefits under corrupt superiors, reflecting opportunistic graft at operational levels.[23] Figures like Ryan Pilkington, evolving from a juvenile OCG associate to a uniformed officer by series 6, further exemplify the syndicate's recruitment pipeline, transforming street-level recruits into institutional threats.[24] Guest characters typically anchor seasonal investigations into specific corruption vectors, often as high-ranking officers entangled with the OCG or personal malfeasance. Notable examples include Lennie James as DCI Tony Gates in series 1, whose laundering of Hunter-linked funds via charity fronts demonstrates financial enablers of infiltration; Keeley Hawes as DI Lindsay Denton in series 2, scrutinized for lapses in Hunter's protection detail; Daniel Mays as DS Danny Waldron in series 3, driven by vendettas against historical cover-ups; Thandie Newton as DCI Roz Huntley in series 4, compromising evidence in a murder probe; Stephen Graham as DS John Corbett in series 5, as an undercover operative turned rogue; and Kelly Macdonald as DI Jo Davidson in series 6, navigating OCG ties amid DNA links to Hunter's legacy.[23][25] These roles, drawn from acclaimed performers, collectively portray corruption's breadth—from tactical alliances to institutional blind spots—without implying uniform prevalence, as AC-12's pursuits yield convictions grounded in forensic evidence.[26]Production
Conception and Development
Jed Mercurio, a former junior doctor who gained prominence writing medical dramas such as Bodies, conceived Line of Duty as an exploration of police corruption and accountability, drawing initial inspiration from the 2005 Metropolitan Police shooting of Jean Charles de Menezes.[2] This real-world incident prompted Mercurio to investigate institutional failures in law enforcement, despite lacking prior experience in police-themed narratives, marking a shift from his medical drama roots to procedural thrillers focused on systemic issues within UK policing.[2][27] Mercurio developed the series concept around Anti-Corruption Unit 12 (AC-12), emphasizing internal investigations into officer misconduct amid broader concerns over police integrity scandals.[27] The BBC commissioned the project through World Productions for a five-episode first series, targeting BBC Two as a mid-tier drama slot, with production emphasizing taut, interview-driven storytelling to heighten tension.[28] The series premiered on BBC Two on 26 June 2012, establishing its format of serialized corruption probes without a standalone pilot episode.[28] Rising viewership, culminating in the highest ratings for a BBC Two drama in a decade by series three, prompted a strategic network shift; the BBC announced on 6 May 2016 that subsequent series would air on BBC One to maximize audience reach while freeing BBC Two for emerging content.[29] This relocation began with the fourth series in 2017, reflecting the program's evolution from niche thriller to flagship procedural.[29]Writing and Storytelling Approach
Jed Mercurio's scriptwriting for Line of Duty emphasizes a tightly plotted, mystery-driven structure, where each season revolves around AC-12's investigation into police corruption, escalating through inciting incidents like ambushes or betrayals that link disparate characters and propel the narrative forward.[30] He sustains tension by adhering to one story advancement per scene, avoiding over-reliance on single revelatory facts, and incorporating authentic procedural jargon advised by police consultants to ground the drama in realistic investigative processes.[31] This approach ensures revelations emerge empirically from evidence, such as forensic details or witness inconsistencies, rather than contrived coincidences.[30] Interview sequences under Regulation 15 form pivotal dramatic climaxes, often spanning 10 pages or more in scripts—expanded from shorter formats in Series 1—to amplify suspense drawn from real interrogation tactics, where suspects and officers parry with concealed motives and procedural minutiae.[32][31] Mercurio heightens uncertainty by structuring these as verbal duels, testing character integrity through high-stakes choices, such as affiliations with Freemasonry or hidden alliances, which mirror the ambiguity of real-world probes.[32] Non-linear elements and red herrings further emulate investigative fog, with misdirections like engineered suspicions on figures such as Superintendent Ted Hastings or overlooked clues (e.g., golf clubs symbolizing illicit ties) delaying resolutions until evidence aligns in finales.[30][32] Initially conceived for standalone arcs per season to allow fresh cases, the storytelling evolved into interconnected lore by Series 2, reusing antagonists like Tommy Hunter and threading ongoing threats such as the 'H' conspiracy across investigations, prioritizing institutional patterns of inertia—evident in recurring procedural lapses—over isolated heroic triumphs.[31][33] This shift, refined post-recommission based on prior events' implications, enables sustained multi-season engagement without diluting per-season momentum.[31]Casting Process
The principal roles in Line of Duty were filled by Martin Compston as DS Steve Arnott, Vicky McClure as DI Kate Fleming, and Adrian Dunbar as Superintendent Ted Hastings, forming the core AC-12 team across all series. Compston, initially hesitant due to a demanding film commitment, was persuaded by actor Craig Parkinson—a friend and series regular—and secured the part after a single audition employing a south-east London accent. McClure obtained her role following a challenging audition marked by inadequate preparation, yet her selection reflected creator Jed Mercurio's emphasis on performers capable of embodying characters and informing subsequent script refinements. Dunbar's early casting influenced Hastings' profile, including the adoption of a Northern Irish origin proposed by the actor himself to enhance depth.[34] Mercurio opted for relatively youthful actors in 2011 to depict driven, less seasoned anti-corruption officers, allowing for character evolution over multiple seasons. Casting director Kate Rhodes-James managed selections, prioritizing alignments that supported narrative authenticity and performance intensity. The leads' off-screen interactions, such as shared living and outings during Belfast-based filming, bolstered their evident team dynamic.[11][35] Authenticity in portrayals extended to vocal realism: Compston, a native Scot, rigorously practiced Arnott's dialect via repeated listenings to expert recordings over months of production. Dunbar preserved his inherent Northern Irish inflection for Hastings, arguing it conferred greater credibility to the character's authoritative presence. No prerequisites for actors' prior law enforcement involvement were specified, though Mercurio's own emergency services background informed procedural details indirectly shaping role demands.[36][37] Each season featured a high-caliber guest lead as the central suspect or antagonist, chosen for proficiency in layered depictions of institutional compromise—exemplified by Thandie Newton's DCS Roz Huntley in series 4 and Kelly Macdonald's DCI Jo Davidson in series 6. These decisions hinged on actors' proven range for morally intricate police figures, with Mercurio bypassing auditions for established talents like series 1's Lennie James as DI Tony Gates. Such targeted casting ensured escalating stakes without diluting the leads' continuity.[38][34]Filming and Technical Production
Principal filming for the first season occurred in Birmingham, England, utilizing local architecture to depict urban police environments.[39] From the second season onward, production shifted to Northern Ireland, primarily Belfast, which served as a stand-in for nonspecific British cities, leveraging the region's versatile urban and institutional sites such as the Invest Northern Ireland Headquarters for police facilities and Belfast Central Library interiors.[39] [40] This relocation capitalized on Northern Ireland's production incentives, including UK-wide film tax relief at 25% of qualifying expenditures and additional support from Northern Ireland Screen's funding mechanisms, alongside the area's controlled shooting permissions and lower logistical costs compared to mainland UK hubs.[41] [42] Cinematography emphasized gritty realism through handheld camera work, which imparted a documentary-like immediacy and unease, particularly in interrogation scenes mimicking confined, high-stakes encounters.[43] Low-key lighting schemes further amplified institutional drabness, with subdued illumination casting shadows to underscore moral ambiguity and procedural tension, as noted by director of photography Ruairí O'Brien in discussions of balancing multi-angle shoots under constrained conditions.[44] Season 6 production faced significant interruptions from the COVID-19 pandemic; filming, which had commenced in early 2020, was suspended on March 16, 2020, amid government lockdowns.[45] Resumption occurred in September 2020 under strict protocols, including remote operation innovations for stunts and modifications to interview formats to minimize close contact, culminating in a wrap by November 2020 and a delayed premiere in March 2021.[46] [47] [48]Music and Soundtrack
The score for Line of Duty was composed by Carly Paradis, a Canadian-born British composer who developed the main theme on piano after immersing herself in the scripts to capture the emotional core of the characters and narrative tension.[49] Her approach involved initial piano sketches followed by studio experimentation with instrumentation, blending orchestral elements such as dark brass with electronic textures to evoke a sense of contemporary unease and nostalgia.[50] This fusion supports the series' procedural intensity, particularly through recurring motifs that build suspense via circling melodies and authoritative swells, amplifying paranoia during key sequences like AC-12 interviews.[49] A soundtrack album, Line of Duty (Music from the Original Series), featuring 23 tracks primarily from the first two series, was released on April 1, 2014, by World Soundtrack.[51] Notable cues include "The Ambush," which underscores ambush operations with escalating pulses, and "You're Finished," highlighting climactic confrontations tied to themes of institutional betrayal and personal isolation.[52] Paradis continued scoring subsequent series, maintaining the established sonic palette to reinforce the evolving arcs of corruption and moral ambiguity without separate per-season releases.[53]Episodes
Season Summaries
Series 1 (2012)The inaugural series of Line of Duty, comprising five episodes each approximately 60 minutes in length, aired on BBC Two from 26 June to 31 July 2012.[54] It centers on the formation of Anti-Corruption Unit 12 (AC-12) and their initial probe into a fatal shooting during a police operation gone awry, scrutinizing the actions of Detective Chief Inspector Tony Gates, a seemingly effective officer leading a major organized crime squad.[55] The investigation uncovers potential procedural lapses and ethical dilemmas within Gates' team, marking AC-12's entry into exposing internal police misconduct.[56] Series 2 (2014)
Broadcast on BBC Two from 12 February to 19 March 2014, this six-episode series, with runtimes around 60 minutes, shifts focus to Detective Inspector Lindsay Denton following a deadly ambush on a police convoy transporting a protected witness, resulting in multiple officer fatalities.[57] AC-12 delves into Denton's decision-making and possible links to compromised operations, broadening the scope to witness protection failures and inter-departmental tensions.[58] The narrative escalates scrutiny of mid-level command structures amid revelations of coordinated threats against law enforcement.[59] Series 3 (2016)
Airing on BBC Two from 24 January to 28 February 2016 over six episodes of similar length, the third series examines Superintendent Patrick Dryden's oversight of a high-profile murder investigation, probing inconsistencies in evidence handling and officer conduct.[60] AC-12's inquiry reveals potential cover-ups tied to historical cases, intensifying the unit's confrontation with entrenched institutional protections.[61] The plot advances themes of loyalty and betrayal within senior ranks, building on prior exposures of localized corruption. Series 4 (2017)
Premiering on BBC One on 26 March 2017 and concluding on 30 April, this six-episode arc, each roughly 60 minutes, targets Detective Superintendent Rosalind Jackson amid suspicions arising from a counter-terrorism operation and related deaths.[62] AC-12 navigates alliances and deceptions, uncovering patterns suggesting deeper networks influencing police intelligence and operations.[10] The investigation highlights vulnerabilities in specialized units, escalating from individual accountability to systemic interdependencies. Series 5 (2019)
The fifth series, broadcast on BBC One from 31 March to 5 May 2019 across six episodes averaging 60 minutes, follows AC-12's pursuit of Detective Chief Inspector Patricia Carmichael, triggered by a raid yielding questionable outcomes and officer-involved shootings.[63] Emphasis falls on interrogation tactics and evidential chains, exposing rifts in command hierarchies and potential manipulations of internal reviews.[61] This installment amplifies the conspiracy's breadth, linking disparate incidents to coordinated efforts undermining anti-corruption efforts. Series 6 (2021)
Comprising seven episodes aired on BBC One from 21 March to 2 May 2021, with extended runtimes up to 90 minutes in the finale, the sixth series investigates Detective Chief Inspector Joanne Davidson's leadership of a murder inquiry, amid heightened threats from organized crime groups.[64] AC-12 confronts pervasive influences across police divisions, culminating in revelations of widespread operational compromises.[65] The narrative peaks with intensified focus on institutional resilience against entrenched criminal-police entanglements, drawing prior threads into a broader web of accountability challenges.[10]
Episode Structure and Key Arcs
Episodes of Line of Duty typically commence with an inciting incident, such as a flawed police operation or unexplained death implicating potential corruption, prompting AC-12 to initiate scrutiny through evidence gathering, including forensic reviews and witness debriefs.[8] This phase transitions into montage sequences depicting investigative diligence, such as timeline reconstructions and surveillance analysis, which underscore procedural authenticity while escalating personal risks to the core team of Superintendent Ted Hastings, DI Kate Fleming, and DS Steve Arnott.[8] Central to each episode are extended interview confrontations under caution, where scripted exchanges expose contradictions, with their positioning calibrated to resolve prior ambiguities and amplify suspense.[8] Narrative momentum builds via iterative revelations, often weaving in subplots of internal AC-12 dynamics or suspect backstories, before concluding with cliffhanger disclosures that link immediate cases to latent threats.[66] This format sustains a compressed pacing, characterized by dense plot layering and abrupt twists, which viewers have noted for generating unremitting tension without diluting investigative logic, as evidenced in feedback praising the equilibrium of revelation and restraint across installments.[67][65] Spanning seasons, key arcs revolve around a persistent conspiracy tying episodic misconduct to the organized crime group (OCG), facilitated by infiltrated senior officers, with the identity of "H"—a designation for the principal protector within a quartet of compromised figures—serving as the connective enigma.[68] This thread progresses through layered disclosures, where standalone probes unearth ties to the OCG's infiltration tactics, such as coerced intelligence sharing or fabricated alibis, culminating in partial unmaskings that perpetuate institutional distrust without full resolution.[8][66] The arc's design prioritizes evolving stakes over predetermined endpoints, ensuring each season's case advances the broader causal chain of corruption while introducing discrete antagonists to refresh scrutiny.[8]Release and Distribution
Broadcast Timeline
Line of Duty premiered on BBC Two on 26 June 2012 with its five-episode first series concluding on 24 July 2012.[55] The second series aired from 12 February to 19 March 2014 on the same channel. Series three broadcast from 24 January to 28 February 2016, achieving its finale viewership peak of 9.1 million, which contributed to the decision to move the programme to BBC One for series four due to sustained high ratings exceeding 5 million per episode in later outings.[69] [70] The shift to BBC One occurred with series four, airing from 26 March to 30 April 2017.[71] Series five followed on BBC One from 31 March to 5 May 2019.[72] Series six, delayed by COVID-19 production disruptions, ran from 21 March to 2 May 2021, with its opener drawing 9.6 million viewers and finale reaching 12.8 million overnight—a record for the series and BBC drama in over a decade.[73] [69] [74] Intervals between series typically spanned one to two years, shaped by writer Jed Mercurio's parallel commitments, including Bodyguard in 2018 between series four and five.[6]| Series | Channel | Premiere Date | Finale Date | Key Viewership Metric (millions) |
|---|---|---|---|---|
| 1 | BBC Two | 26 June 2012 | 24 July 2012 | Average ~4 (finale) |
| 2 | BBC Two | 12 February 2014 | 19 March 2014 | Grew to ~5 (later episodes) |
| 3 | BBC Two | 24 January 2016 | 28 February 2016 | Finale 9.1 |
| 4 | BBC One | 26 March 2017 | 30 April 2017 | ~7-8 average |
| 5 | BBC One | 31 March 2019 | 5 May 2019 | ~7-9 peaks |
| 6 | BBC One | 21 March 2021 | 2 May 2021 | Finale 12.8 (overnight) |
International Availability and Streaming
Line of Duty has achieved international distribution through linear television channels and on-demand streaming platforms. In the United States, the series aired on BBC America beginning with its debut season in 2014, followed by availability on streaming services including BritBox, Hulu, Acorn TV, and Peacock.[75] [76] Season 6 premiered on BritBox in the U.S. and Canada in March 2021, shortly after its UK broadcast.[76] In Australia, Canada, New Zealand, parts of Europe, and Asia-Pacific regions, the series became accessible on Netflix following a 2020 distribution deal between World Productions and the streamer, with Seasons 1–4 initially rolled out and later expansions including subsequent seasons.[77] ITV Studios facilitated global sales for Season 6 after the collapse of distributor Kew Media in 2020, enabling broader licensing to international broadcasters and platforms.[78] Non-English markets feature subtitled versions on select platforms, such as Apple TV, which provides closed captions and subtitles in languages including Spanish.[79] Dubbed editions exist in limited capacities, primarily for DVD releases, though streaming prioritizes original audio with subtitles.[80] The streaming release of Season 6 in 2021 amplified international engagement, drawing new audiences in regions with prior episodic access via cable or delayed broadcasts, and fostering online discussions that extended the show's reach beyond the UK.[76][78] This accessibility contributed to sustained global interest, evidenced by platform-specific viewership upticks and fan communities on social media post-finale.[81]Home Media Releases
The home media releases of Line of Duty encompass DVD and Blu-ray editions issued shortly after each season's broadcast, typically including individual season sets and cumulative box sets for ownership. These formats have been distributed primarily in the UK through labels like BBC Worldwide and Acorn Media, with Region 2 DVDs and Blu-rays accommodating PAL standards.[82][83] Series six, the final season, became available for digital purchase on 3 May 2021, preceding physical releases of the Blu-ray edition on 31 May 2021 and the DVD on 28 June 2021.[84][83][85] A comprehensive Blu-ray box set compiling series one through six followed on 12 July 2021, spanning 12 discs and approximately 30 hours of content.[86][82] Earlier seasons received analogous annual physical releases post-airing, with complete series DVD box sets also produced, such as a 13-disc edition encompassing all six seasons.[87][88] Digital download options for permanent ownership emerged alongside physical media, available via platforms like iTunes and Amazon. For instance, series two was offered for digital purchase on iTunes starting 24 November 2014.[89] Complete series compilations have since been listed for digital acquisition on Amazon, enabling archival without subscription dependencies.[82] These releases prioritize consumer access to uncut episodes, though specific bonus content details vary by edition and are not uniformly documented across sources.Reception
Viewership Data
The viewership of Line of Duty demonstrated a marked upward trajectory across its seasons, with consolidated figures from the Broadcasters' Audience Research Board (BARB) reflecting initial audiences of approximately 4 to 5 million for series one episodes in 2012, escalating to averages exceeding 12 million by series five in 2019.[90] Series six, aired in 2021, achieved peak consolidated viewership, including live broadcasts and 7-day catch-up via BBC iPlayer, with the premiere episode reaching 13.1 million viewers and the finale accumulating 15.24 million, marking it as the highest-rated drama episode of the 21st century to that point.[91][92] Significant contributions to these figures came from BBC iPlayer streams, where series six became the platform's most-watched drama boxset of 2021, with the opening episode alone garnering 9.2 million views and the full series totaling 137 million streams.[93][94] BARB's 28-day consolidated metrics for the series six premiere further indicated 14.6 million viewers, underscoring the role of on-demand viewing in amplifying reach beyond linear broadcasts.[95]| Season | Average Consolidated Viewers (millions) | Peak Episode (millions) | Notes |
|---|---|---|---|
| 1 (2012) | ~4-5 | N/A | Modest debut, primarily linear TV.[90] |
| 5 (2019) | 12.85 | N/A | Substantial growth pre-iPlayer dominance.[90] |
| 6 (2021) | ~13-15 | 15.24 (finale) | Record highs driven by iPlayer; most-watched 21st-century drama.[92][96] |