Blue Lights series 3: Plot, start date, location, and start date

Blue Lights series 3: Plot, start date, episodes, and location as Cathy Tyson and Michael Smiley join line-up

Helen Fear | 11:16am Sat 6 Sep | Updated 4:29pm Mon 15 Sep

Blue Lights series 3 is happening, with two new faces joining the cast of the BBC One police drama in 2025.

The Beeb has announced that Cathy Tyson and Michael Smiley have joined the award-winning drama, which has started filming in and around Belfast as of now.

So what else do we know about Blue Lights series 3, including cast, start date, location, and plot? Here’s everything we know so far…

Michael Smiley as Colly in Blue Lights series 3 — Michael Smiley joins the cast of Blue Lights series 3 as Colly [Credit: BBC/Two Cities Television]

Is there a Blue Lights season 3?

Blue Lights will be returning in the future for a season 3 AND a season 4. The Beeb announced the decision even before the critically-acclaimed Belfast police drama had aired its second season.

Writers Declan Lawn and Adam Patterson said at the time: “We’re thrilled that the BBC is committing to Blue Lights in this way. From the beginning, we wanted to write a show that had scale and ambition in its storytelling. And this decision gives us everything we need to do that.”

We’ve now been told that the third run has started filming.

What’s the plot?

Fans will know that the excellent police drama follows three new PSNI probationary recruits as they navigate their way through policing a uniquely complex city.

Series 3 catches up with Grace, Annie and Tommy two years into their jobs as response officers. They are now accustomed to life under the blue lights…But, we’re told, “their work will take them into a sinister world hidden behind the veneer of middle-class life, the world of the accountants and lawyers who facilitate organised crime”.

The old political and criminal order has gone and a new global gang rule Belfast, bringing danger closer to home for our officers than ever before.

Cathy Tyson as Morgan in Blue Lights series 3 — Cathy Tyson takes on the role of Morgan in Blue Lights series 3 [Credit: BBC/Two Cities Television]

Who’s in the cast of Blue Lights series 3?

Leading lady Siân Brooke will reprise her role as Grace Ellis in series 3 of Blue Lights. She’s best known for playing Karen Newman in Trying, Siân in Doctor Foster, and Deirdre Young in Good Omens.

Of course, the series wouldn’t be the same without her co-star Martin McCann, who plays Stevie Neil. He played Bobby Barrett in Marcella, and most recently popped up as Wee Pat in Say Nothing.

Katherine Devlin will return as Annie Conlon. She recently played Emma Stoke in Day of the Jackal.

Meanwhile, Nathan Braniff will play Tommy Foster. It was his first ever TV role. Dead and Buried actress Joanne Crawford returns as Helen McNally.

Andi Osho’s Sandra Cliff will be back, too, having made the decision not to leave Belfast in the emotional series 2 finale. Sick Note’s Hannah McClean is also set to return as Jen Robinson.

Blue Lights series 3 will also star Frank Blake as Shane Bradley, Abigail McGibbon as Tina McIntyre, Dearbháile McKinney as Aisling, and Andrea Irvine as Nicola Robinson.

Who guest stars?

BBC One recently announced that Boiling Point and Vera star Cathy Tyson will join the cast of Blue Light series 3.

She’ll be joined by Michael Smiley, who recently played morally ambiguous Roger Muldoon in Bad Sisters.

Nick Lambon, BBC Drama Commissioning Editor, UK & Northern Ireland, said: “It is a delight to watch Cathy and Michael seamlessly join our talented cast. The arrival of both characters marks the start of the most ambitious Blue Lights series yet, which will leave fans questioning everything they think they know about the response officers they have come to love…”

Nathan Braniff as Tommy in Blue Lights series 3 — Actor Nathan Braniff returns as Tommy in [Credit: BBC/Two Cities Television/Peter Marley]

How many episodes is it?

Blue Lights series 3 will be six episodes of one hour each. The first three episodes will be directed by Jack Casey while actor/director Angela Griffin will direct the last three episodes. Of course, Angela is most famous for her acting roles in Corrie, and Waterloo Road.

Declan Lawn and Adam Patterson, co-creators and executive producers, said: “We can’t imagine better custodians of our creative vision than our brilliant series three directors Jack Casey and Angela Griffin. It’s a privilege, as ever, to be back in Blackthorn.”

Is Blue Lights worth watching?

Blue Lights is arguably one of the best police dramas on TV right now. Dare we even compare it favourably to the likes of Happy Valley, and Line of Duty. It’s about policing in a troubled area but, more than that, it’s about human relations and connections.

Series 2 averaged 5.6 million viewers across the series, while episode one’s 7 million made it the BBC’s fourth biggest drama launch in 2024.

In Northern Ireland, it was the biggest drama across the whole market (broadcasters and streamers), across 2023 and 2024.

Katherine Devlin as Annie Conlon in Blue Lights series 3 — Actress Katherine Devlin is back as Annie Conlon in Blue Lights series 3 [Credit: BBC/Two Cities Television]

When will Blue Lights be back in 2025? What’s the series 3 start date?

Blue Lights filmed in and around Belfast earlier this year, where the show is set. It will be landing on BBC One in the autumn schedules – so watch this space.

Blue Lights series 1 aired in March 2023, with series following in April 2024. Although BBC One has not confirmed am exact start date for series 3 yet, we’d be surprised if it doesn’t land very soon.

Series 1 and 2 are currently available to watch on BBC iPlayer.