The Bafta-winning show, which is set in modern-day Belfast and follows rookie cops, reeled audiences in over two dramatic series since its launch back in 2023.
Published: 05:33 EDT, 29 September 2025 | Updated: 05:34 EDT, 29 September 2025
It's been more than a year since it was last on screen, but now popular BBC cop thriller Blue Lights is back for more with a third series.
The Bafta-winning show, which is set in modern-day Belfast and follows rookie cops, reeled audiences in over two dramatic series since its launch back in 2023.
Fans won't have to wait long now to get back in with the drama, as the third instalment returns to screens tonight (Monday) on BBC One.
Series three will follow the now no-longer newbie officers, Trying actress Sian Brook's Grace, Katherine Devlin's Annie and Nathan Braniff's Tommy.
They will be joined by a host of familiar faces, as well as a handful of new recruits, for the latest storyline, based in the sinister world hidden behind the shiny front of middle-class life.
The trio will take a deep dive into the murky world of the accountants and lawyers who facilitate organised crime in the city.
The Bafta-winning show, which is set in modern-day Belfast and follows rookie cops, reeled audiences in over two dramatic series since its launch back in 2023
Popular BBC cop thriller Blue Lights is back for more with a third series
The synopsis teases: '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.'
It will also continue to follow the fall-out from Grace's former career as a social worker, that has seen the police officer come face to face with children from the system caught up in organised crime after suffering difficult upbringings.
The new episodes will see Grace encounter a child she formerly worked with, Lindsay, who has been caught up in the web of one of the gangs.
And it's likely that Grace's romance with Stevie could be picked up where things are left off, following their romantic smooch at the end of series two.
Actress Sian previously teased that season three will be 'intense' and 'surprising'.
She told the RadioTimes that the series 'blows it out the water' compared to previous series, adding: 'I don't know how these guys get better and better, but they do.
'There's a lot of care that's gone into making them and they're very individual and so people have related to them, they want to know what happens, where the story ends.'
Her co-star Nathan added: 'It's the best so far this next one, I would say, so we're all super excited for everybody at home to see it.'
Sian Brook's Grace and Nathan Braniff's Tommy will be back for more as part of the action
Katherine Devlin's Annie will also be back as part of the star-studded cast, which this time will feature both familiar and new faces
Alongside the familiar three main charcters, Joanne Crawford will return as Helen McNally, Andi Osho as Sandra Cliff and Frank Blake as Shane Bradley.
While Dune: Prophecy's Cathy Tyson and Bad Sisters star Michael Smiley, have been confirmed to be part of the new faces joining the cast.
Written by the team behind Novichok drama The Salisbury Poisonings, fans previously compared the high-octane drama to fellow popular BBC cop series, Line of Duty.
Taking to X following the series two debut, one fan penned: 'Blue Lights just maybe the replacement we needed for Line of Duty', as a second agreed: 'Definitely one of the best police programmes to be produced in a while.'
Series two began with a time jump from the first series, which saw the tragic death of fan-favourite, PC Gerry Cliff.
Explaining their reasoning for the time jump, co-creater and writer Adam Patterson said: 'The whole creative team made a conscious decision to move the story a year on.
'Part of the reason for that is that if we had picked it up right away then every story would have been consumed by Gerry and we needed the actors to go on different journeys.
'In a lot of ways he still lives on in many of our characters but by moving the story on a year it allows us to look at different parts of the police and parts of the city.'
Blue Lights returns tonight on BBC One and BBC iPlayer.