Since his directorial debut The Iron Giant in 1999, Brad Bird (The Incredibles, Ratatouille, The Simpsons) has been challenging audiences’ expectations of what animated films can do … and who they can be for. “There’s a big chunk of people who don’t watch animation,” Bird tells Tudum. “That’s a group I’m anxious to persuade because it’s an amazing art form that is way too limited in people’s minds.”

Bird’s latest, Ray Gunn, which will beam onto Netflix Dec. 18, is perhaps the two-time Academy Award–winning director’s boldest play at blasting through those limitations. Ray Gunn has been percolating in the director’s mind for more than 30 years — since even before The Iron Giant — and in those decades, despite the many transformations in animation technology and the film industry at large, the fundamental concept has never changed. “It was always meant to be a blend of sci-fi and classic detective movies from the ’40s,” says Bird. “The elevator pitch I came up with is The Maltese Falcon meets Buck Rogers.”

Although there’s still plenty of action that’ll appeal to viewers of any age (“It’s a good popcorn movie,” Bird promises), Ray Gunn will be a different kind of offering, proving that animation isn’t just a kids’ medium. Read on for more.

What is Ray Gunn about?

In Metropia, a gigantic city in an alternate future as seen from 1939, private eye Raymond Gunn (Sam Rockwell) is drawn into a case involving aliens, murder, and a multimedia star named Venus Nova (Scarlett Johansson).

In visualizing Metropia, Bird tapped into an Art Deco-inspired, pre-World War II vision of the future — optimistic and upward reaching. “What if cities just kept getting taller and taller and more streamlined, and cars could fly, and people had jetpacks as an alternative form of getting about?” says Bird.

Who is in the Ray Gunn voice cast?

Oscar winner Rockwell (The White Lotus, Three Billboards Outside Ebbing, Missouri) voices Ray Gunn, a small-time private eye in a time when most detective work has been taken over by machines. “Sam is a wonderful actor, and he does a fantastic job giving the animators a bar to reach in terms of performance,” says Bird.

Academy Award nominee Johansson (Jurassic World Rebirth, Marriage Story) voices Venus Nova, the world’s most famous pop star whose scandals threaten to destroy her career — and may even cost her her life. Johansson says, “Having the opportunity to collaborate with Brad Bird is a career milestone for me. I have loved his work my entire life. This project is so uniquely special because it is a total realization of where Brad is currently on his artistic journey. I can’t wait for audiences to see this extraordinary animation that looks like nothing else out there.”

Grammy winner and Oscar nominee Tom Waits plays Eyera, Ray’s most trusted compatriot, who also happens to be a one-eyed alien. “I've long admired [Tom] on several levels,” says Bird. “He's one of these multi-talents like Scarlett who does music and acts. And he's always interesting on screen. It was a blast to work with him.”

More casting announcements are still to come, but the voice talent all have something in common. “The main thing is, in animation, you want a voice cast that animators can listen to over and over again,” explains Bird. “A line that takes an actor five seconds to say may take an animator three weeks to animate, and they will listen to a line hundreds of times in order to get the cadence in order so that their gestures support what’s happening, and keeping them inspired is a huge win. All the best voice actors do that.”

When is the Ray Gunn release date?

Ray Gunn’s future is closer than ever — the film’s long journey to screens will finally be complete in December. “It’s been a challenge to do something new and get it made on a big scale, so I was really happy that Netflix saw potential in this,” says Bird. “Animation as a medium is too interesting to limit what kind of stories can be told.”

Ray Gunn will stream Dec. 18, only on Netflix.