Siân Brooke: Blue Lights gave me new respect for my policeman dad's sacrifice

Siân Brooke sits in her London home, a director's wife with two children and a dachshund, talking about why the world needs people who still believe they can change things. Her character in Blue Lights, a social worker who becomes a police officer in Belfast, is exactly that kind of person—principled, slightly naive, the sort who gets things done anyway. As the BBC One drama returns for its third series, Brooke has been thinking about idealism, about the weight of work that doesn't make headlines, and about her own father, who spent more than twenty years on the Staffordshire police force.

When Blue Lights first landed on screens, Brooke worried the police procedural genre was already oversaturated. But what struck her was the specificity of the writing—the way even minor characters carried real weight, real interiority. More than seven million people watched the first episode. The show's creators, Adam Patterson and Declan Lawn, had done the kind of deep, journalistic research that shows: they understood modern Belfast, understood what it means to be a police officer there now, understood that the city is far more complex than the shadow of the Troubles that still clings to it. Three hundred and two officers were killed during the Troubles themselves. The risks have diminished, but they haven't vanished. Officers still check under their cars every morning, whether they're heading to work or not. In 2023, shortly before Blue Lights premiered, Detective Chief Inspector John Caldwell was shot multiple times outside a sports centre in Omagh, County Tyrone, after finishing a youth football coaching session. He was off-duty. He was a target anyway.

Brooke grew up seeing beyond the uniforms and the cars. She went to work with her father on bring-your-kid-to-work days and saw the backstage of policing—the interview suites, the tape machines, the gravity of ordinary people in extraordinary circumstances. Her father had started on the beat, then moved into CID. He made a deliberate choice, she thinks now, not to bring the worst of his days home with him. He compartmentalized. He loved watching Juliet Bravo. But as Brooke has gotten older, and especially since taking on this role, he's begun to tell her more about the cases he carried. She finds herself thinking: God, you were dealing with that, and then you came home and were just Dad. The weight of it hits differently now.

Her father's generation processed trauma the way many did—they dealt with it, they moved on, they used dark humour as a pressure valve. Brooke saw that gallows humour woven through the Blue Lights scripts and it drew her in immediately. In professions where the stakes are high and the threats are real, dark comedy becomes a survival tool. It's how people stay human when the work is dehumanizing.

Brooke herself is a quiet observer by nature. She was a quiet child. At ten years old, she went to see a musical called Banana Boys at a small, crumbling arts centre, and the lights went down and something lit up inside her. That was it. She went to RADA, then spent a decade in bit parts on solid crime dramas—Foyles War, Midsommer Murders, Lewis—learning her craft in the margins. She was terribly self-critical then, constricted by her own doubt. She had to learn to fail, to work alongside older actors who could teach her. Sheila Hancock took her under her wing, took her to dinner, talked to her about the long arc of a career. The best advice Hancock gave her: don't take it too seriously, keep your sense of humour, hold onto your common sense. Later, Brooke's role as Eurus Holmes in Sherlock—Sherlock's secret sister, opposite Benedict Cumberbatch—was called a star-making turn. She'd auditioned for three different characters before learning they were all pieces of one extraordinary part. She had to keep it secret while filming, telling everyone she was doing a police drama in Cardiff.

Brooke has always carried a slight unease about working in the arts. Both her parents served their communities—her father in policing, her mother as a teacher. She winces at old interviews where she's been asked whether playing gritty characters takes a toll. Yes, it does. But she goes home at the end of the day. Nobody's life was actually in danger. The pandemic shifted something in her thinking, though. During lockdown, people turned to television. Drama sustained them. It became a connective force when everyone was isolated from everyone else. TV drama began to lead the national conversation rather than follow it. Look at the changes sparked by Mr Bates vs. the Post Office, by Adolescence—even people in the industry were surprised by the ripple.

Blue Lights has had that same effect. Without overstating it, Brooke believes the show has educated people about what Northern Ireland is now, what it means to be a police officer in 2025. She knows people who've changed their minds about the job because they watched it. In her own way, then, she's doing what she's always believed in: getting things done.