Joker: Folie à Deux makes it clear that Lady Gaga's Harley Quinn is only just getting started, and I really need more

The following contains spoilers for Joker: Folie à Deux.

Joker: Folie à Deux might be a courtroom drama, but it's also a surreal, dreamy, and twisted love story between Joaquin Phoenix's Arthur Fleck, AKA the Joker himself, and Lady Gaga's Harley "Lee" Quinn.

As a Lady Gaga superfan of 15 years (a Little Monster, to use the correct terminology) and a massive Harley Quinn fan, it's safe to say this was one of my most anticipated movies of the year. I was counting down the days to see Gaga shine as Lee, and I came away from the movie convinced it was perfect comic book movie casting – Gaga completely embodies Harley Quinn's flair for the dramatic, strange vulnerability, and deeply disturbed psyche. Plus, she aces those musical numbers, if there was ever any doubt.

Always leave them wanting more, as they say, and Joker: Folie à Deux certainly left me craving another movie with Gaga's Lee. In fact, the way the film ends is almost like a passing of the torch – a trading of the jester hat, if you will. While Arthur becomes disillusioned with his Joker persona, Lee falls deeper and deeper into her own alter-ego, even walking out of Arthur's trial when he turns his back on the Joker.

This all culminates in Arthur, fleeing the court after it was suddenly blown to smithereens, finding Lee on that famous staircase. Arthur is excited, believing they can now finally have a life together. But Lee doesn't want Arthur: she wants Joker. She sings 'That's Entertainment,' despite Arthur begging her to speak to him, tired of the singing, and leaves him alone on the stairs to be arrested. Ultimately, Arthur meets his death in Arkham, stabbed repeatedly by another inmate furious with him for abandoning the Joker.

Clown Princess of Crime

As I watched Lee leave Arthur to his end, though, I couldn't help thinking she was only just getting started. In this final scene between the ill-fated lovers, Lee fully embodies the classic Harley Quinn style: a full face of smudged clown makeup, the harlequin-inspired outfit, even a new, messy haircut. While Arthur is near bare-faced, in a grey suit, and speaking normally, Lee is in her regalia and still in that dark, dreamy headspace where all the world's a stage, and she is the star performer.

It's a transformation that happens slowly across the movie, as Lee, infatuated with Arthur, urges him to succumb to his Joker persona and gradually styles herself with more and more dramatic outfits and makeup. When she sees Arthur for the last time, dooming him by refusing to run away with him, it's as if she has taken his supervillain status for herself.

It's not just a dynamic present in the movie, either. Gaga's album 'Harlequin,' released to tie in with the movie, features a cover of the song 'The Joker.' In the movie, this is sung by Joaquin Phoenix in a dream sequence in the court, and it's a more traditional rendition of the song, drawing out the tragedy of being one of life's jokers – a down on his luck, lonely clown. Gaga's version, though, is rawer and more aggressive, without the melancholy. She practically growls her way through the second pre-chorus before letting out a sudden, spine-chilling laugh. "The Joker is me," Gaga declares, in a theatrical, terrifying assertion, a darkly triumphant inverse of the original meaning: she's one of life's Jokers, and she's thrilled about it. It's the kind of thing I could imagine Lee singing to herself as she abandons Arthur on those stairs, taking the essence of the Joker for herself.

The groundwork is already there for an unhinged, villainous Harley Quinn, too. We learn in the film that Lee lied to Arthur about being forcibly committed by her mother, being responsible for arson, and living near his old neighbourhood. In reality, she went to grad school for psychiatry – a nod to Harley's classic origin, which sees her as a psychiatrist falling in love with the Joker while he's her patient – lives with her parents in a rich area, and voluntarily committed herself to Arkham just to meet Arthur. This is clearly a clever, scheming woman, perfectly primed to take over the mantle as the Clown Prince(ss) of Crime.

It's also a smart twist on the usual dynamic between Harley and Joker, which involves Harley in a manipulative, abusive relationship. A more calculating, devious Harley, herself the bad influence on Arthur , is fascinating, and I'd love to see how her story could play out now that Arthur is dead. What can she do next? Well, it certainly seems like Gotham is hers for the taking.

So, while the book is closed on Arthur Fleck, it feels as if a new chapter has only just begun for Lee Quinzel. It's one I really hope I get to see play out on the big screen someday, too, so Gaga's Lee can fulfil all that deliciously villainous potential. The Joker is she…

For more on the movie, check out our Joker: Folie à Deux review for our verdict, or settle in for a marathon with our guide on watching the DC movies in order .

You can also see all the Joker: Folie à Deux Easter eggs , the Joker: Folie à Deux ending explained , whether there'll be a Joker 3 , and if there is a Joker: Folie à Deux post-credits scene .