She has captivated viewers with her portrayal of rookie police officer Grace Ellis in the BBC's gripping cop drama Blue Lights, which recently returned to our screens for a second season. And Siân Brooke tells us here how her father’s career in the police force helped inspire her performance.
But the actress, 44, who has also appeared in Dr Foster and Sherlock, says her greatest role is being a mum to Ben, 11, and Archie, nine, her sons with her husband, actor and award-winning theatre director Bill Buckhurst, who is currently at the helm of the West End production of Sister Act: The Musical.
Siân, your dad was in the police. Did that background help you prepare to play Grace?
My dad was a police officer and my mum was a teacher, so I was brought up in a household where I very much knew right from wrong. In some way, I think that's in there, as well as trying to humanise a profession that is so often defined by a uniform. You see the uniform first and sometimes forget that there’s a real person behind that.
How long do you usually spend filming Blue Lights in Belfast?
We kicked off last August and finished in December, so it's around four or five months in Belfast with the team. They're the most amazing cast and crew. It's an old cliché, but it's like a family. We've been together for two years, making seasons one and two, so to think we can spend another two years [with the show booked to return for series three and four] is a happy prospect.
You must miss your sons when you’re away…
My biggest job is being a mum, so the hardest part is that I have to be away from them, but I have an amazing husband who holds the fort.
I come back at weekends and they come over. They love Belfast and we travel around Northern Ireland as well. They're already saying: 'When are we going to go back?'
Can you pinpoint a role that changed your career?
Sherlock was instrumental in putting me on a bigger platform, in terms of what the show was like when it came out and when I joined it. It was everywhere. There was Sherlock fever, so to be part of that was something I'll treasure, as well as being trusted by [show co-creators and writers] Steven [Moffat] and Mark [Gatiss] with that role.
Roles like that don't come along very often, so I'll always look back and think: 'Wow, I did that.'
Having played Sherlock Holmes's evil sister Eurus, you must have had some interesting responses from the show's fans…
I've had lots of people coming up and wanting to share their love of the show, and it's great to have that feedback. I never went into acting to be recognised, so it's not something that sits comfortably with me.
I've taken to wearing a baseball hat a lot. But equally, what's lovely is that people are so passionate about a show that they want to come up and say: 'I love it.'
How do you stay grounded?
My two kids keep me grounded. They don't enter into that world; they definitely say it how it is.
In terms of future plans, are you interested in returning to the theatre at some point, or perhaps directing?
Both of those things. I'd love to get a project of my own off the ground. Maybe it's something about entering my 40s and having had more than 20 years in the business, but now I feel ready. I have some seeds of ideas; my husband is a director so we're working on some stuff.
The stage is where I started out and earned my stripes, so I'd love to get back to there. It's been a few years.
With Blue Lights returning for two more series, what can you reveal about the next instalment?
All I can tell you is that it's going to be a cracker. You will not be disappointed.
Blue Lights is available to watch on BBC iPlayer.