Image copyright Getty Images/Lionsgate Image caption Megyn Kelly (left) and Charlize Theron, who plays her in Bombshell

There are two different types of bombshell in Bombshell.

The Oscar-nominated film depicts the 2016 sexual harassment scandal at Fox News, which led to the firing of the network's then CEO Roger Ailes and rocked the media industry.

But the film's title also refers to the female employees who were involved.

The right-wing news network is famous for hiring young, attractive and usually blonde anchors to front its broadcasts.

"The movie's title is clever, cleverness being its modus operandi," said the New York Times. "The story, after all, is about female employees who, with icy smiles and iron ambition, worked for a conservative political force who institutionalised the harassment of women."

Former presenter Gretchen Carlson was the first to blow the whistle on Ailes, claiming she was fired from the channel for refusing his sexual advances.

Several other women then came forward, among them the high-profile anchor Megyn Kelly, to add their names to the list of women he abused.

Charlize Theron has been widely praised for her portrayal of Kelly in Bombshell, which has netted her a nomination for best actress at the Oscars.

Playing a real-life person, especially one who's still active and high-profile, can be a particular challenge for an actor. But when it came to researching the role of Kelly, Theron explains: "I didn't meet her, by choice.

"Listen, the whole thing is pretty overwhelming," she continues. "It took me a while to wrap my head around playing her for many reasons. But I think the biggest one is that she's so well known. And it's contemporary, it's of this moment, and whether you like her or not, you know her face, you know what she sounds like, and there was really no getting around that."

Theron has been praised by critics not only for her acting performance, but also for her physical likeness to Kelly, which was achieved with the help of prosthetics from make-up artist Kazu Hiro.

"The transformation is so authentic, so on point, it's unnerving," said Empire's editor Terri White.

"The first thing you notice about her deep-dive performance as Megyn Kelly is that you don't see Theron at all," agreed Peter Travers in Rolling Stone. "Through voice, posture, wardrobe, and the genius prosthetic make-up, Theron is Kelly."

Image copyright Lionsgate

Theron, who also co-produced the film, explains she wrestled with Kelly's politics before she agreed to the role.

"There are things she's said in the past that have bothered me," Theron says. (Kelly's previous controversies include her defence of people dressing in blackface as a character for Halloween and her comments about Santa Claus being white.)

"But the more I zeroed in on what the film was, [I realised] it wasn't a Megyn Kelly biopic, it's about a year-and-a-half at Fox, and she was a part of many other women who experienced this thing and then ultimately succeeded in doing something that was thought of as impossible.

"And so once I narrowed it down to that, it became easier for me to make it about that, and whether I have issues with her or not, she was part of something that will I think be a historical marker for women's rights."

Ailes was fired from Fox News as a result of the allegations, receiving $40m (£31m) in severance pay. He died a year later, aged 77. Several women who filed lawsuits against him received damages from Fox News.

The fact that the Ailes scandal pre-dated #MeToo makes it all the more significant, as the climate was not what it became a year later, when allegations against movie mogul Harvey Weinstein sparked the movement which would bring down several big-screen heavyweights.

Image copyright Getty/Lionsgate Image caption Roger Ailes (left) died in 2017. He is played in the film by John Lithgow (seen with Theron)

The film largely keeps things focused on the scandal and doesn't venture into being a study of the goings on at a right-wing news channel.

"Is Bombshell hard enough on Fox News? Difficult to gauge, because it's so much more focused on the internal culture than the product they put out in the world," wrote Alison Willmore in Vulture.

"The film presents familiar figures as waxlike caricatures," she wrote, adding: "When it comes to Trump, the movie is oddly unspecific about the role Fox News played in the election."

But perhaps that doesn't matter, given how resonant the film feels as a result of its focus on sexual harassment.

"This conversation is happening in real time, and I think without that this movie wouldn't have the power that it does," acknowledges Theron.

"It was really strange to make the film and to slowly see these things all kind of unravel. I remember sitting in the make-up trailer and watching male actors talk negatively about this movement, that they thought was dangerous and was excluding men and was over-correcting, and it was infuriating.

"The Harvey [Weinstein] thing happened and that was really big, and when the tapes of the women were released, I think that's when we realised that we were part of telling a story which was somewhat the origin story of this whole movement, and we didn't know that before."

How does she respond to those suggestions that it has led to over-correcting? "I mean, listen, I feel like, in context, when you really look at it at from 30,000 feet in the sky, what's happened to women in toxic workplaces for years and years, a little over-correcting is the least we can do," Theron says.

Image copyright Getty Images Image caption Charlize Theron was nominated for best drama actress at the Golden Globes earlier this month

Considering Kelly isn't well known in the UK, and Fox News isn't consumed widely, is Theron aware that Bombshell could be a harder sell for British audiences?

"Totally, of course, we have all of those conversations," she replies. "But then you realise that you guys have the linchpin, Rupert Murdoch," she says, referring to Fox's ultimate chief, who also owns British newspapers including The Times and The Sun. "So I think that's enough information, that's all you need to know.

"You don't really need to know anything about Fox," she continues. "Because this is such a non-partisan... this is not a political film, it's not about Fox per se, really it's just the time and the place in the world. This is something which I think is reflected in so many different workplaces.

Before we leave, we ask which news outlets Theron consumes herself.

"CNN," she replies initially. "But I also like to have varied news sources, I watch a lot of right-wing political shows and news programmes because I think it is important for us to see how the other guy is talking. So there's never been a part of me that's just like 'don't want to see it, don't want to hear it, only want to get what I believe'.

"I think it's hard to have any kind of real conversation about real issues unless you really know where the other person is coming from, what ground they're standing on. You have to be willing to listen. I think a lot of the time we just want to state what we believe and the importance of that, and we don't listen enough."

Bombshell is released in the UK and Ireland on Friday 17 January.