The brilliant Babylon exposes the grim truth about Golden Age Hollywood

Stop me if this sounds familiar. A kindly matinee idol and a perky young starlet cross paths in Golden Age Hollywood. Through a whirl of raucous parties and comically disastrous film shoots, his career slumps while hers soars. The backdrop is one of social and technological upheaval – and the studios, bless them, are fumbling to catch up. That’s right: it’s the plot of Singin’ in the Rain. And also A Star is Born, twice, in 1937 and 1954. And 1931’s What Price Hollywood. And 2011’s The Artist. In other words, the film business obviously loves to tell this story about itself. But what’s in it for them? And why do we, their customers, keep eating it up?

These are questions to which Babylon offers some fairly lively answers. The new film from La La Land’s Damien Chazelle is a lavish, hyper-energised epic of old-movie-world misbehaviour: a three-hour storm of sex, drugs, elephants, cocktails, gambling, snake fights, and assorted bodily expulsions. The title invokes Kenneth Anger’s scandalous gossip book Hollywood Babylon – and maybe also the debauched ancient city itself, which in the Bible was undone by talk.

Largely set in the 1920s and 30s, Chazelle’s film seems at first to be following the same old rise-and-fall plot, using the coming of the talkies as its pivot point. Giving the kind of charming performance that sneaks up and moves you without you even noticing, there’s Brad Pitt as Jack Conrad, a silent-era heartthrob in the John Gilbert vein. And Margot Robbie plays Nellie LaRoy, a Clara Bow type whose slinky sensuality on camera preempts the coming Jazz Age loosening of morals.

Rather than trotting out the fable one more time, however, Babylon exposes it as the bittersweet lie it always was – showing an industry that’s corrupt, exploitative and riddled with bigotry, but also wily enough to disguise its own chew-’em-up-and-spit-’em-out business model as the very fairy tale that keeps the show on the road. Though set almost a century before the downfall of Harvey Weinstein, it’s an acutely sharp #MeToo film. And its manic swagger and mischief – channelled from Martin Scorsese pictures like GoodFellas and The Wolf of Wall Street – dares you not to delight in the delinquent behaviour which today would get its participants cancelled in a trice.

Newcomer Diego Calva is superb as Manny Torres, the Mexican immigrant at Babylon’s heart who wants to work in the movies and will take any job going to make sure of it. He becomes a personal assistant to Pitt’s Jack, and later still a producer, but when we meet him, he’s wrangling entertainment for a party thrown by Don Wallach (Jeff Garlin), a more-than-faintly Weinsteinian studio chief.

Working with his regular director of photography Linus Sandgren, Chazelle captures this crazed event on a camera that soars and plunges through the chaos as if it’s spinning a web around the revellers. Justin Hurwitz’s score, booming away throughout, is addictively, adrenalisingly mad, often sounding like someone is trying to drown out the La La Land soundtrack with a second, louder copy of the La La Land soundtrack.

During this gilded bacchanal, Robbie’s Nellie is spotted by a producer whose current leading lady has just inconveniently overdosed. So after two hours’ sleep, she’s playing a floozy in a barroom scene, where her risqué manner and ability to cry on cue make her a star at a stroke.

As admirers of Robbie’s work in Once Upon a Time in Hollywood and The Wolf of Wall Street already know, there may be no working actress better at weaponising gorgeousness, and as Nellie, she wields hers like a flamethrower, torching the screen and the careers of her primmer co-stars with it. But there is grippingly subtle sadness and fury here too: the way Robbie has Nellie look at her grasping father/manager (Eric Roberts) during a drunken pool party escapade hints at an unhappy backstory you suspect neither would be able to speak aloud.

Chazelle splits the film cleanly into three hour-long acts, with the talkies arriving at the start of the second. Much of the comic business from this point on mirrors classic scenes from Singin’ in the Rain, except here it’s crueller and more desperate: Chazelle relies on us noticing this, before bringing the parallels full circle in a 1952-set finale so audacious I’ve been waking up chuckling about it for weeks.

There are lighter satirical swipes at aspects of Hollywood behaviour which apparently haven’t changed much: one subplot involves a black trumpeter (Jovan Adepo) who becomes the star of a series of jazz-themed musicals, only to be patronised at a soirée by rich white liberals who congratulate themselves on supporting his work.

But the film is thrillingly reckless enough to make you genuinely dread what’s coming next. A sickeningly tense late sequence, possibly patterned after the cocaine house scene in Paul Thomas Anderson’s Boogie Nights, features Tobey Maguire as a decomposing libertine who pledges to take Manny to the last “proper party” in Hollywood.

What our hero witnesses there, in a series of tunnels just beyond the city limits, is essentially vaudeville gone to hell – but perhaps not too different in spirit to what’s going on in the studios just down the road.

Yet even knowing just how gruesome things can get in this factory, Manny finds the product irresistible. And that’s where the astonishing finale leaves him: transported in spite of himself. Like all the rest of us – like star-struck suckers everywhere – he can’t help coming back for more.

In cinemas from Jan 20