“It feels so great to walk into a room full of people and really flip your lid,” says Jenna Coleman. “Just let loose with all that female rage.”

The 38-year-old actor is describing filming a scene for the new BBC crime drama The Jetty, in which her character – a police detective called Ember – confronts members of her small town over their tolerance of sexual relationships between older men in the community and teenage girls in her daughter’s year at school.

“Even though I was acting and there were cameras there, I could feel the tension rising,” she remembers. “A woman shouting, laughing, losing control while speaking truths people don’t want to hear… it makes people uncomfortable doesn’t it? I wonder why that is… are we just expected to be more polite, more likely to follow societal norms?”

The Jetty is a show designed to discomfort viewers with difficult questions. But those questions are wrapped up in a classic murder mystery that begins when a true crime podcaster starts digging into a cold case – the unsolved disappearance of a local schoolgirl. When the community closes ranks, the podcaster talks Coleman’s character into questioning the people she grew up with. “People,” she notes, “who can tease her with old playground rumours of where she lost her virginity, so she’s got to fight to maintain her authority.”  

Over the phone Coleman – pregnant with her first child – admits that she burns off her own rage in the gym. Confrontation isn’t her cuppa. Although she made her name with quite fiery turns in shows such as Doctor Who (as the Doctor’s plucky companion Clara) and Victoria (as a formidable Queen Victoria), the petite, poised Coleman is a more introverted character. 

“So in real life,” she winces, “if I wanted to take people on the way Ember does in the show, I’d probably have a long conversation with myself first. I’d sit down and think about how best to put both sides across calmly. Then I’d get upset afterwards, if I felt I hadn’t been able to express myself.”

She sighs. “But I do believe it’s healthy to get angry – everybody should do it – otherwise you’ve got suppressed emotions and you don’t move on. I ended up having some great conversations about rage with [the show’s writer] Cat Jones.”

Jones, who spent five years working as a prison officer before becoming a full-time writer in 2013, explains that The Jetty had its seeds in how movements like #MeToo got her thinking about some of the girls she went to school with, who began dating older men in their mid-teens. She remembers one girl who didn’t tell her parents about the older boyfriend, and one who did. 

“In that case,” she says, “the parents felt their daughter was safer with an older man, that he calmed her down and she was less likely to be out behaving wildly because she was with him.”

Jones shrugs. “I kept wondering how those women might reflect on those relationships now: would they feel they’d been abused? Would they have ongoing trauma? Or would they be happy with their teenage choices? I think in one case there is a chance that my old classmate is still with that guy…”

Archie Renaux, who play’s Ember’s junior partner in The Jetty, also recalls the moment when girls at his school began seeing “way older” men. “It was about Year 11, I think,” says the 26-year-old. “Us boys at that age we were like, ‘eugh’” – he pulls a queasy face – “that’s quite mad. But those men have got cars, money, and schoolboys can’t compete. I don’t know what those older guys wanted. A kind of control? To me it didn’t sit well at all.”

Girls in Year 11 can be 16 years old – above the legal age of consent. So this is where Jones says things get “knotty”. “The law is one guideline of course. But it’s a pretty blunt tool which doesn’t provide any kind of moral guideline, does it?” As Coleman says: “It is really hard to put a blanket rule, a set rule on sexuality at that age, isn’t it? Those mid-teen years are a period where people are developing at completely different rates and levels. I found myself looking at the kids I know of that age and asking myself: ‘How would this apply to this person, to that person’ and so on? It felt really conflicting and confusing.” 

Viewers of The Jetty are left to ask questions about which of the characters (both the younger girls and the older men) have enough maturity and agency to make their own choices. “I deliberately didn’t use words like paedophilia – which means an attraction to prepubescent children anyway – in the script because I didn’t want to make things black and white,” says Jones. “I wanted to explore the morally grey area you get when girls are sexually mature but not. There is something primal about sex and sexual relationships, which leaves me wondering how you impose rules on something so instinctive – so about how different people feel in the moment. I’m not claiming to have the answers but I do think it’s a very interesting conversation to have.”

In the show, Coleman’s character, Ember, met her older husband when she was 17 and became a mother at 18. She looks back on a happy family life and struggles to square that experience with how she feels watching her daughter’s peers getting out of older men’s cars. Ember challenges her own mother, Sylvia, about her lack of protective instincts.

The Jetty has been released just a month after Netflix’s Céline Dion documentary, in which we’re reminded that, back in the 80s, the Canadian chanteuse met her manager/future husband when she was just 12 years old, with the pair getting together when she was 19. Dion describes her long career as her husband’s masterpiece, not her own. Like the fictional Ember, the real Dion reflects on a long happy marriage to the father of her children. But Jones’s script argues that “men like that can make you feel like the most special person in the world, so long as you’re doing what they want”. 

Today Jones is fascinated by Dion’s story. She thinks “it’s possible somebody like Céline Dion never stopped doing what her husband wanted, so he always made her feel special? We can’t know. And attitudes to age-gap relationships have changed over the past 20 years.” She also says she “felt sorry for Ember’s mother in the show. She is a woman who had grown up with limited choices and had tried to embrace her daughter’s choices, her freedom, her love affair. As a mother myself” – Jones’ daughter is nine – “I thought it was a good idea to put two generations of mothers on screen, both getting stuff wrong. I mean, motherhood is always imperfect. You turn up every day and you go to bed reflecting on what you got wrong that day.” 

The teenage girls portrayed in The Jetty are just as flawed as their mothers. One of the teenage characters shown dating an older man is smart, manipulative, beautiful and comes from a wealthy family. “You could argue she grooms herself,” says Jones. “She behaves abusively herself and I’m pleased we put a complicated ‘victim’ like that on screen because abusers often don’t target the obviously sweet, innocent girls – they target the girls people are less likely to believe. Even though I think the girl in my show is actually incredibly vulnerable – partly because she doesn’t realise that about herself.” 

Renaux agrees. “You don’t realise what you don’t know at that age. I look back and, even at 21 I was still making odd decisions. Your brain just isn’t mature enough to make responsible choices. My girlfriend now is three years older than I am, though. I think becoming a father three years ago probably helped me mature a bit…” But Renaux is also already struggling with his “threenage” daughter’s wilful moments. He pulls a comedy shudder at the thought of exerting parental control when she’s 15. 

Renaux’s character, Hitch, is one of the show’s good men – but he’s not sure when to call out his old friends on sexist banter. “I didn’t want to write a show about villainous men,” laughs Jones. “I like men. But I don’t like the sexist ‘bantz’ culture which creates the conditions for abusers to thrive. I had to deal with lots of sexist banter in prisons – from the male staff as well as the inmates. Women don’t want it but we don’t have the energy to call it out all the time. That’s why the show asks when good men can do that.” 

There’s also a male character in the show who doesn’t act on his attraction to a woman when it is ethically inappropriate. “He’s honest about how he feels and he holds a moral line and walks away. It’s massively unsexy of him in some ways because I’m sure the viewers might want these two to get together. I hope people watching feel the chemistry. But he’s doing the right thing and it’s very cool of him.”  

Jones’ script asks questions about reform and forgiveness. “As somebody who has worked in the prison service, I think that if you don’t believe people are redeemable then there is no incentive to do better.” But she’s also aware that her show features a man who is never held to account for his actions. “I think he changed and became a better man,” concludes Jones. “But I want viewers to be left asking: ‘Shouldn’t redemption come at a price?’ And I want them to ask how we can protect our teenagers and teach them to recognise coercive behaviour.” 

‘The Jetty’ begins on BBC One at 9pm on Monday. The full series will be available on BBC iPlayer that morning