Before anyone can make the Harvey Weinstein movie – and won’t the ending of that one be everything? – here comes a story of toxic masculine power and female justice, played out in the public arena.

Probably less well-known as a real-life case here than in America, this is about former Fox News chief Roger Ailes and the cases of sexual harassment brought against him by his own high-profile TV news presenters, Megyn Kelly and Gretchen Carlson (brilliantly played by Charlize Theron and Nicole Kidman respectively).

There’s a third blonde on this scene, Kayla Pospisil, a wholesome MidWestern gal played by Margot Robbie teetering between innocence, ambition and crushed hurt. She’s a composite of several real-life characters but gets the movie’s best and most startling scene, being ‘auditioned’ by Ailes in his office, a man who likes his female anchors to show off their legs.

Ailes is portrayed by John Lithgow, usually such a likeable indeed loveable actor, here bloated under rubbery prosthetics, and sitting in his chair, breathing heavily as he tells the pretty young blonde to hitch her skirt up, higher and higher, while he snorts approval like some snuffling old warthog.

The way Robbie plays it, it’s a terrifying moment, one that takes you more than anything I’ve seen recently into the heart of what the #MeToo movement is all about, properly questioning the lines between sex, professionalism, men and women, power and ambition.

You might say it’s a Bombshell of a moment. It’s such a good title for the film – referring not only to a shocking news story but also, since the 1940s, to the ‘quaint’ old expression used to describe female figures of such explosive sexuality they leave men uncontrollable – Jean Harlow, Jayne Mansfield, Marilyn Monroe, Anita Ekberg, Brigitte Bardot, Diana Dors are just a few.

It was also the title of a fine 2018 documentary about Hedy Lamarr, which revealed the great beauty’s surprising and mostly uncredited gift for science and technology, one which actually helped win WWII and invent wi-fi.

Back to these bombshells and the case brought against – and bringing down – Ailes of course shocked America in the summer of 2016, mainly because Megyn Kelly was one of his favourite stars. She’s played by Theron with admirable skill, not always likeable but smart and strong, using voiceover and staring at us through the camera, narrating us through the hierarchies of Fox office power politics.

And that’s where the film wobbles. It’s caught between smart, talky comedy and genuine outrage. When it goes for a jokey tone, you sense its rightful anger softening… and that didn’t feel right to me at all.

It’s directed by Jay Roach, who gave us the Austin Powers movies and Meet the Parents, but who has leaned towards more political material recently, although always with an eye on the absurdity of human behaviour. And he’s right in that respect – how did we let our workplaces get like this? How did dodgy men get so many people do their bidding?

So, as it tries to summon up the atmosphere of the time and the pressure these women came under, the movie itself feels rather smitten with the energy and deadline glamour of a newsroom, leaving it flailing when attempting to explain away certain behaviours. It’s slick and sick at the same time.

Maybe that’s the point – this is how these beasts prowled and operated on everyone, infecting a whole culture. And now the blondes are fighting back. So though it may not land all its punches, when Bombshell’’s good, it’s a knockout.