As if Todd Phillips and Joaquin Phoenix’s take on the Joker wasn’t already intriguing enough, the filmmaker and star are taking a considerable creative swing with sequel Joker: Folie À Deux – stuffing their follow-up film with song-and-dance numbers as Phoenix’s Arthur Fleck forms a romantic connection with Lady Gaga’s Harley ‘Lee’ Quinzel. But as unusual a combination as it might seen, it came out of a playfulness that the pair established while making the first Joker – feeling out the tone and the character, and imagining what might come next.

As Phillips tells Empire, conversations about how Arthur Fleck might fare in other scenarios were rife on Joker. “Joaquin and I talked about another one the whole time while we were making the first movie, just because we love the character,” he says. “We were obsessed with Arthur. We would almost joke about it: ‘Oh, we should take Arthur and we should do this.’” And as Phoenix tells it, the ideas were always intentionally bonkers. “I had a curiosity about going further with the character,” he laughs. “It felt like you could put him into almost any situation, and I would be interested to see how he would navigate it. I mocked up all of these posters of films that have already been made, like Rosemary’s Baby and Godfather, and I put Joker in them and I gave them to Todd.” There were even intergalactic gags. “There was a running joke of, ‘What about Joker in space?’,” he says. “But yeah, I was fascinated by where he would end up.”