After 15 years of international success on the stage with powerful dramatic plays including random and generations, London-based Debbie Tucker Green makes her screenwriting and directing feature debut with Second Coming. It’s a hushed and disturbing parable starring Nadine Marshall as Jax, a married woman who mysteriously falls pregnant. It doesn’t seem that her partner Mark (Idris Elba) is the father, so who is? Perhaps the clue is in the title.

Green is famously publicity-shy, so I was pleased to be granted a rare interview at her agent’s offices in leafy West London. She’s far from retiring in person, though, speaking in a rapid-fire London patter, with her hands making a furry of arcs and gestures in tandem with her words.

After working in theatre for so many years, how did you come around to the idea of making a film?

It’s a mountain to climb from thinking you’ve got a film – or even a script – to getting it made. Random started off as a stage play, and ran for years. I had no intention of it going on to screen because I don’t think things always translate very well [Tucker Green adapted it for Channel 4 in 2011]. It was just apparent when I was writing that Second Coming was a feature. I think in pictures, so I saw lots of air around this story. Visually, it had a different tone.

With regard to industry practice, how did you find the process differed between stage and cinema?

For me, it’s story and script first, and the other industry drama comes after.

There’s more people involved in film, even when it’s low-budget – more fingers in the pie. So that was a little newer. That was probably the biggest difference, people putting in their two-pence worth. If you ‘get it’, then it’s fine, we can work on the script; but if I don’t think you’re ‘getting it’, then we’re in a bit of trouble…

With Random, at Channel 4, we had some rough and tumble. But we turned it around quite quickly. It was a case of “I haven’t got time for politeness, let’s just get on it.” I’m not saying it’s a horrible thing. There are a few more zeroes involved in film, and people are a bit more jumpy, so I understand it. You have to push back though, because, trust me, I recognise my film! [laughs]

Kai Francis-Lewis and Nadine Marshall in Second Coming

Second Coming is purposely ambiguous. Was there any pressure on you to explain more to the audience?

I thought the film was quite definitive! But it’s been interesting watching it with audiences, because it’s more open-ended than I’d thought, which is fine. It’s sparked debate, with people having little rows about what they thought happened. But there wasn’t much pressure on me about the ending. For me it was interesting to watch this woman over her pregnancy and not be sure. It’s all played out in a day-to-day way; a lot of it for Jax is behind the eyes; her trying to keep up.

And Nadine Marshall is especially good in a tricky role…

She’s all right [laughs]. No, I’m joking. The part wasn’t written for her. I don’t write for actors. The script was there, I’d worked with her before. There was a thought process: she was right, agewise, for one.

And whoever played Jax, Mark and the kid… you had to feel it before you could see it. Sometimes I don’t always believe family units on screen. I was still thinking about combinations. I can’t remember at what stage we cast Kai [Francis-Lewis, as son JJ], but things started falling into place. I hadn’t worked with Idris before, and Kai had only done one job. The brief to the casting director was that I just wanted a regular kid who goes to drama club once a week or whatever – nothing against signed-up stage-school kids.

Your dialogue is rhythmical and intricate. Is your writing more influenced by music than other playwrights?

I definitely love music, and what it can do. There’s something for me about the playfulness of dialogue; music reflects on language definitely, whether it’s kids or grown-ups. It’s something that we have that’s very flexible.

Yet the film gets quieter and quieter as we go through. You’ve got a character who becomes more internal. There’s something quite powerful about having the time, and space, to watch her do that.

Idris Elba and Nadine Marshall in Second Coming

I wrote for this magazine in 2013 about Horace Ové’s Pressure [Endings, S&S, December 2013], and how it’s depressingly rare to see everyday black British life – in this case a family of West Indian heritage – represented on film. Too often, I feel, we still see black British representation pegged around certain limited issues like criminality. Your film was so moving for me because it was just like going around to my Jamaican grandmother’s house. Was this a consideration for you?

For me it’s about this particular family, they’re just regular folks. I’m not looking to represent the whole, because everybody lives differently. It wasn’t a huge “I must do this, that and the other,” but rather I just wanted to stay true to these characters; it so happens they are of specific heritage. To me it’s important these characters have their foundation.

People have told me things like you’ve just done, which is great. But you need to go and talk to the commissioners, innit! People who’ve got the money to fund stuff. There are stories out there to be told, and the talent is out there.