THE FINAL ACT PART I

The Final Act Part I  is a 2025 American action film directed by Todd Phillips and Christopher Nolan and written by Christopher Nolan. A direct sequel to 2020's The Killing Grin, it is the fourth film in the Gotham City Sirens franchise and stars Kaya Scodelario, Jessica Rothe, Samuel L. Jackson, Aisha Hinds, Idris Elba, Elisabeth Moss, Brenton Thwaites, Imogen Poots,  Ian Ziering, Jessica Chastain, Halle Berry, and Margot Robbie. It follows Jamie Reid and everyone who survived an encounter with the Gotham City Sirens finally deciding to ban together to defeat the Gotham City Virus once and for all. The first film in the two-part finale of the Gotham City Sirens Saga.

The film was acclaimed by critics, with praise for the narratives, the performances of various actors and actresses, the visual effects, and comedic moments.The Final Act Part I was released on December 13,2025, by Warner Bros. Entertainment, New Line Cinema, and DC Films Entertainment.

Production
Development

In January 2016, it was announced that Todd Phillips, Director of Joker, was working on a new DC film.

By July 2023, the studio had begun active development on both The Final Act films and Phillips and Nolan were confirmed as directors, with production to begin in early 2024. After being cast as the lead, Kaya Scoldelario stated in an interview, "Nolan told me that this was the biggest project and best project that he ever worked on, and it was 100% true," when was asked about what Christopher Nolan's thoughts were on the film. Warner Bros. stated that the film would be split into two parts with the second part coming out next year.

Pre- Production