British Crime Drama · BBC One · Season 4 Guide
Blue Lights
Blue Lights is the award-winning Belfast police drama following three former rookie officers — Grace Ellis, Tommy Foster, and Annie Conlon — as they navigate the dangers and complexities of policing in Northern Ireland. Season 4 premiered on BBC One on September 29, 2026, and arrives on BritBox in the US on November 12, 2026, with six episodes released weekly through December 17. This season brings the return of Richard Dormer's Gerry Cliff, whose murder trial exposes long-buried secrets that threaten both the police and Belfast's criminal underworld. Seasons 1–3 are available to stream on BritBox now. Widely hailed as one of the freshest British crime dramas in years — gritty, warm, and genuinely unpredictable.
About the show
Blue Lights was created by Declan Lawn and Adam Patterson, former BBC investigative journalists who drew on their own years in Belfast for the show's post-Troubles setting. Siân Brooke, Martin McCann, Katherine Devlin, and Nathan Braniff lead the cast as three former rookie officers and their experienced colleague, Sergeant Stevie Neil. The series won Best Drama Series at the 2025 BAFTA Television Awards.
Where to watch Season 4 in the US
BritBox
Season 4 premiered in the UK on BBC One/iPlayer September 29, 2026, and arrives on BritBox in the US November 12, with new episodes weekly through the finale on December 17 · Seasons 1–3 available now · Subscription required
View BritBox Options →Streaming availability in the US can change. Check the linked service for the current season and episode selection. Checked October 2026.
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BritBox is the service you need for Blue Lights. If you also watch other British dramas, Acorn TV and PBS Masterpiece can be added as Prime Video channels too, so everything sits on one watchlist.
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Buy the DVDs
Individual/complete-series DVDs available · Check current sellers and formats
Shop Blue Lights DVDs →New Viewer's Guide
New to the Series? Start with Season 1
Blue Lights is serialized, not a procedural-of-the-week — the same three rookie officers, Grace, Tommy, and Annie, carry the story across all four seasons, and supporting characters and consequences from earlier seasons keep resurfacing. Starting with Season 1 is the way to get the full weight of Season 4's callbacks, including the return of Gerry Cliff's story, played by Richard Dormer.
Best Seasons, Ranked
British TV Hub's editorial opinion, not an official ranking — in order of how well each season showcases the show. Kept spoiler-light.
Blue Lights at Its Most Ambitious
The show pivots from street-level crime to the wealthier, more insulated world of organized crime — accountants and lawyers who help it operate — with Dana Morgan and Helen McNally driving the new threat. Widely seen as the series finding a bigger, more confident gear.
The Essential Starting Point
Grace, Annie, and Tommy begin as rookies at Blackthorn Station, pulled into conflict with the McIntyre crime family. The cleanest introduction to the show's characters, setting, and tone — and required viewing before Season 4's biggest storyline.
The Highest Stakes Yet
Three years into the job, Grace, Tommy, and Annie face a new threat the police can barely control, while the murder trial of Gerry Cliff reopens a long-buried secret that causes chaos across both the police and Belfast's criminal underworld. It premiered on BBC One September 29, 2026, to strong early reaction in the UK; this ranking will be revisited once US viewers have had a chance to watch.
A Solid Middle Chapter
A body linked to a former soldier draws Stevie and Grace into rising loyalist paramilitary tensions, while new recruit Shane Bradley joins the team. A steady continuation rather than a showstopper, but it sets up threads Season 3 pays off.
Main Characters and Cast
Siân Brooke
Constable Grace Ellis — a former social worker turned probationary officer, now three years into the job and one of the show's emotional anchors. Also known for Sherlock and Trying.
Martin McCann
Sergeant Stevie Neil — the trio's supervising sergeant, pulled deep into the undercover side of the job. Also known for Trespasses and Hostage.
Katherine Devlin
Constable Annie Conlon — a young recruit who's grown into a confident officer over three seasons on the beat. Also known for The Day of the Jackal and Vikings.
Nathan Braniff
Constable Tommy Foster — the third of the original rookie trio, now facing the limits of frontline policing alongside Grace and Annie.
Richard Dormer
Gerry Cliff — killed in Season 1, Dormer returns for a flashback-driven Season 4 storyline as Cliff's murder trial reopens long-buried secrets. Also known for The Day of the Jackal, Game of Thrones, and Fortitude.
Joanne Crawford & Andi Osho
Helen McNally and Sandra Cliff — Helen is the officer promoted to lead a secret investigation into Belfast's criminal underworld; Sandra, Gerry Cliff's widow, is drawn back into the story as his trial reopens old wounds.
Cathy Tyson & Michael Smiley
Dana Morgan and Paul "Colly" Collins — Dana is the private members' club owner at the center of Season 3's criminal syndicate; Colly is a C3 intelligence officer working the police side of the same story.
Frank Blake, Abigail McGibbon & More
The wider Blackthorn ensemble returns for Season 4: Frank Blake as Shane, Abigail McGibbon as Tina, Dearbháile McKinney as Aisling, and Andrea Irvine as Nicola.
Hannah McClean & Jonathan Harden
Jen Robinson and Jonty — a solicitor and a disgraced former Inspector, both drawn into the episode that finally answers questions from Gerry Cliff's past.
What Makes the Series Special
Written by Former Investigative Journalists
Creators Declan Lawn and Adam Patterson spent years as BBC investigative journalists before writing The Salisbury Poisonings, and they draw on their own time living in Belfast for the show's post-Troubles setting — a level of specificity that's rare in TV police dramas.
A Cast That Grows Across Seasons
Grace, Tommy, and Annie aren't reset to rookies every season — their careers, relationships, and the consequences of earlier cases carry forward, with supporting characters like Helen McNally and Dana Morgan building into the story over time.
Belfast, Divided and Changing
Filmed on real Belfast streets, the show treats the city's loyalist and republican communities, and the everyday reality of post-Troubles policing, as central to the story rather than background color.
Setting and Filming Locations
Belfast, Northern Ireland
Blue Lights is filmed on location in and around Belfast, Northern Ireland, using real streets and buildings rather than studio sets for most exteriors — part of why the show feels so grounded in the city.
Watch the Trailer
More Trailers on British TV Hub — Trailers & Previews →
Frequently Asked Questions
How many seasons and episodes does Blue Lights have?
Four seasons so far, with six episodes each. The BBC hasn't announced a fifth season as of October 28, 2026.
When does Blue Lights Season 4 premiere in the US?
Season 4 premieres on BritBox on November 12, 2026, with new episodes arriving weekly through the finale on December 17.
Do I need to watch Blue Lights in order?
Yes, it's recommended. Unlike a case-of-the-week procedural, Blue Lights carries its characters and consequences forward season to season, and Season 4 in particular leans on events from Season 1.
Is Blue Lights based on a true story?
No, it's a work of fiction. But creators Declan Lawn and Adam Patterson are former BBC investigative journalists who drew on their own years in Belfast and real policing experience to shape its setting and tone.
What awards has Blue Lights won?
Blue Lights won Best Drama Series at the 2025 BAFTA Television Awards, beating Sherwood, Supacell, and Wolf Hall: The Mirror and the Light, as well as a Broadcast Award for Best Drama Series or Serial.
Is Blue Lights filmed in Belfast?
Yes. It's filmed on location in and around Belfast, Northern Ireland, using real buildings, pubs, and streets rather than studio sets for most exteriors.
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