The BritBox ‘Blue Lights’ Trailer Promises an Explosive Season 4
'Blue Lights' promises to bring the first three seasons full circle with an explosive trailer.
BritBox is in the middle of a banner year, bookended by two massive BBC hits that brought in more subscribers in 2026 than any previous year: mystery-comedy Ludwig and period drama The Other Bennet Sister. But the service didn’t get there overnight. Since the BBC took full control of the international streaming arm it shared with ITV in early 2024, it’s been building toward this with smart choices like getting in on the ground floor for Blue Lights, the BBC’s most popular police procedural series since Line of Duty. (Speaking of Line of Duty, Season 7 will stream on BritBox in 2027, so be prepared.)
It just so happens that the commitment to Blue Lights is paying off just as BritBox hits new heights. When the BBC first announced it was greenlighting the series through Season 4 before Season 2 even launched, it was a radical departure from the norm. But now that we’ve seen the storyline play out as planned, the multi-season renewal makes far more sense.
The seasons that have aired since have proven the BBC made the right decision, with plot points laid in that first season now coming to fruition. While the series still pulls its punches a little with the main characters – creators Declan Lawn and Adam Patterson simply love their rookies too much to really hurt them – Season 4 seems determined to cement the show’s status as “The BBC’s answer to The Wire.”
(I maintain The Pitt is a far better comparison, especially in how Season 1 positioned star Siân Brooke vis-à-vis how The Pitt has hung its early season on star Noah Wylie.)
Here’s the Season 4 synopsis:
Three years into their jobs as response officers, Constables Grace Ellis, Tommy Foster, and Annie Conlon are operating at their limit, facing a new threat on the streets that the police can barely control. Meanwhile, the murder trial of Gerry Cliff exposes a dangerous and long-buried secret that leads to chaos both inside the police and across the criminal underworld. As they grapple with big decisions about their future, Grace, Tommy, and Annie must find the courage to face the greatest threat they have ever encountered: the truth.
BBC/BritBox
As always, our main quartet of cops includes Brooke (Trying) as Grace, Martin McCann (Wolf) as Stevie, Katherine Devlin (The Day of the Jackal) as Annie, and Nathan Braniff as Tommy. Series regulars returning for Season 4 also include Joanne Crawford (Outlander: Blood of My Blood), Andi Osho (The Sandman), Frank Blake (Say Nothing), Dearbháile McKinney (Kneecap), Andrea Irvine (Call the Midwife), and Abigail McGibbon (Ballywalter).
Season 4 also brings back Richard Dormer (COBRA) and Jonathan Harden (Time), reprising their respective roles as Gerald Cliff and Inspector Jonty for the first time since Season 1; Hannah McClean (Rewarding) as solicitor Jen Robinson since Season 2; plus Cathy Tyson (Dune: Prophecy) as Dana Morgan and Michael Smiley (Bad Sisters) as Paul Collins. Both joined the ensemble in Season 3.
BBC/BritBox
Lawn and Patterson co-created the series with Stephen Wright; the two once again co-wrote all six episodes, with director Angela Griffin returning to split helming duties with Sam O’Mahoney (The Wise Guy), and Brendan Mullin producing. Lawn, Patternson and Wright also executive produce, alongside Louise Gallagher and Nick Lambon for the BBC.
Blue Lights Season 4 debuts as an early access binge on BritBox Premier on Monday, November 2. The series will then debut on regular BritBox starting Thursday, November 12, 2026, and stream one episode a week through mid-December.
Blue Lights
Seasons 1 through 3 are streaming on BritBox.
