Poor Things is a filthy feminist comedy from Greek film-maker Yorgos Lanthimos, a hilarious twist on the Frankenstein story with Emma Stone, Mark Ruffalo and Willem Dafoe.

Last night I saw the most fantastically filthy film of my life. No, I wasn’t on Pornhub or in a seedy Soho sex cinema; I was at Finsbury Park Picturehouse for a preview of Poor Things.

If you’ve seen any of Yorgos Lanthimos’s films before – Dogtooth, The Lobster and Killing Of A Sacred Deer – you’ll know he’s pretty out-there, pretty unconventional. Let’s just say that The Favourite was by a million miles his most conventional film, and that was far from a run-of-the-mill historical biopic or costume drama.

Poor Things takes unconventionality to the next level. It is, as one of its stars Mark Ruffalo said on Graham Norton, “bonkers.” And, frankly, that’s an understatement. So what’s it about?

Where to start?!

Emma Stone, in an astonishing and astoundingly courageous performance that will surely win her awards, plays Bella Baxter, a beautiful Frankenstein’s monster with the mind of a child. In this twisted take on the already twisted Mary Shelley story, Willem Dafoe plays her hideously disfigured creator Godwin Baxter (aka ‘God’ – geddit!) with a terrifying backstory of his own, and Ramy Youssef a medical student, Max McCandles, whom he engages to monitor her progress.

Into their necessarily hermetic world comes Mark Ruffalo’s pompous legal lothario Duncan Wedderburn, determined to introduce Bella to the outside world – and the joy of sex. Or, as she calls it, “furious jumping.”

What follows is an odyssey from a steampunk vision of Victorian London (think: Wes Anderson’s idea of a Dickens adaptation) to Lisbon, Alexandria and Paris (Anderson on acid) with more sex than you can begin to imagine as Bella takes to her new hobby with wild abandon “What I don’t understand,” she says, lying in post-coital bliss after her initial carnal encounter with the wily Wedderburn, “is why people don’t do this ALL the time.”

It’s a good question. Did I mention that there is *lots* of sex in the film, lots of talk about sex, lots of nudity, and that it is not only one of the strangest films you’ll have ever seen but one of the funniest?

If that makes it sound exploitative, really it isn’t: at its heart it’s a powerfully feminist story and a film about freedom, exploring existential ideas, specifically the question of how we (and women in particular) would behave without the brake of social convention and its attendant moral codes. At the same time, it’s depicting the way the world seems so much more wondrous through the eyes of a child before humankind (and men in particular) destroys those wonders with violence and greed.

I hope that doesn’t make it seem like hard work. Honestly, it’s an absolute hoot (albeit with a dark undercurrent) and the actors buy into Lanthimos’s vision completely with outstanding performances that all deserve prizes. It’s got extravagant fantasy sets, wonderful photography (black-and-white for Baxter’s home; colour for the outside world), extraordinary costumes, a hilarious script by Tony McNamara (The Favourite) based on Alasdair Gray’s novel and last, but not least, an immersive score by Jerskin Fendrix making his feature-film debut.

It opens on 12 January and I imagine it will get a bunch of 5-star reviews and one or two 1-star slatings (it already has) but don’t be put off by those. If you want my opinion, you’d be mad to miss it. Did I mention that it’s an absolute filth-fest too?