Joker: Folie à Deux official trailer: Joaquin Phoenix meets his equally mad ... trends now

The official trailer for Joker: Folie à Deux was released by Warner Bros. on Tuesday.

In the highly-anticipated musical psychological thriller film, Joaquin Phoenix, 49, reprises his role as Arthur Fleck, also the Joker, as he meets his match in Lady Gaga, 38, as Harley Quinn.

The trailer for upcoming movie, which is a sequel to the 2019 Joker film and was recently given an official R rating for containing 'strong violence' and 'brief full nudity,' begins with Arthur Fleck in a mental hospital, standing in a cell and seemingly spacing out early in the morning. 

'Wakey wakey,' a guard says while checking up on him. 'Hey Fleck, you got a joke for us today?' 

Arthur is seen being led down a corridor, surrounded by officers, when he and Lady Gaga — who got a multimillion dollar salary for the sequel — as Harley meet each other's eyes through the opening of a door, which is just slightly ajar.

Distracted from singing alongside a group of choir members, she cranes her neck to get a better look at him.

Arthur is also attempting to get a second look at her but is blocked when officers push him forward aggressively.

He is then seen on his solo walk, surrounded by four officers in dark garb and black umbrellas.

With soft piano music in the background, an unseen man's voice remarks: 'We use music to make us whole. To balance the fractures within ourselves.' 

A bird's-eye view shot then shows Arthur throwing his head back to feel the rain falling on his face.

However, the umbrellas are colorful this time, showing that Arthur is living in a different reality.

At a different time, Harley is seen sauntering up the steps of a dark and rainy city as her voice is later heard telling Arthur: 'I'm nobody.' 

Back to present time, Arthur returns from his walk in the rain. He strolls by the choir room once again, which is now empty with Harley standing alone. 

She appears to have been waiting for him and has a mischievous smirk on her face.

She holds up her two fingers, mimicking a gun, and aims it at the side of her head. 

'I haven't done anything with my life like you have.' 

In a scene from his imagination, Arthur is seen in his Joker costume and makeup with a microphone on stage performing.

The patients are watching a movie with nurses keeping watch, but Arthur is imagining his own musical in his head.

Harley is seen sitting at his side and pulls him back to reality when she whispers in his ear: 'Let's get out of here.' 

Cut to another scene from their now conjoined imagination, Arthur has his Joker makeup on and is wearing a suit and tie as he walks up to Harley wearing a slinky gown. 

The pair are standing on a rooftop and slow-dancing under the moonlight.