Neil Patrick Harris is the latest cast addition to the upcoming fourth installment of the Matrix franchise.

Reported by Variety, Harris joins Keanu Reeves and Carrie-Anne Moss, who will be reprising their roles in the film, as well as Yahya Abdul-Mateen II, who was attached to the project as one of the leads last week.

Plot details are currently unknown. While it was rumored a young Morpheus could appear in the movie, sources close to the film would not confirm Harris’ specific role.

Warner Bros. announced in August that a fourth “Matrix” movie is officially in the works, with Reeves and Moss returning and Lana Wachowski on board to write and direct. Warner Bros. Pictures and Village Roadshow Pictures will produce and globally distribute the film.

Aleksandar Hemon and David Mitchell co-wrote the script with Wachowski, who will also produce with Grant Hill. The film is expected to begin production at the beginning of 2020.

The three previous films The Matrix, The Matrix Reloaded and The Matrix Revolutions — have collectively earned more than $1.6 billion at the global box office. All three were written and directed by Lana and her sister, Lilly, and starred Reeves and Moss.