Producer James Cameron and director Robert Rodiguez unite to bring a live-action version of manga warrior Alita: Battle Angel to the screen.

When James Cameron first announced he would make Alita: Battle Angel in 2003, his friend and fellow director Robert Rodriguez was intrigued.

“Jim always has strong females like Sarah Connor and Ripley, so I figured this must be something special because he doesn’t usually adapt other people’s work. He writes his own original material,” Rodriguez tells STACK when we meet in Santa Monica. “So for Jim to want to adapt a manga, there must be something about that character that’s different than something he would have created on his own.”

Even when Cameron offered to show him an early outline, he refused, not wanting to spoil the surprise.

Rodriguez waited and waited… because along the way, a little thing called Avatar happened.

Following the success of Cameron’s 2009 blockbuster, he began feverishly working on four more sequels, while Disney would open a vast Pandora theme park based off the franchise.

But Rodriquez had not forgotten, approaching his friend three years ago; Cameron regretting he would never find time to complete his vision for Yukito Kashiro’s manga, and suggesting his pal take a look at his script.

“When I read the script, I identified with so many of the characters. I identified with the father figure that Christoph [Waltz] plays, who has a young daughter who’s 13 because I have a daughter the same age. I identified with the boy, who is the cool tech kid, and I completely identified with Alita, who is found in a trash heap. She thinks she’s insignificant because she’s discarded and she can’t have anything to offer the world, only to discover instead that she’s extremely powerful, and can actually cause great changes in the world. That’s a very universal story, and I feel like that’s my story too,” says the Sin City director.

(L-R) Producer Jon Landau, James Cameron and Robert Rodriguez

“But that’s what Jim does. He finds stories that people all over the world can identify with and embrace. It has to start with the characters and your love for the character, and your likeability of the character. Alita is a character you can really fall in love with.”

Fast forward, and Rodriguez’s Alita: Battle Angel stars Rosa Salazar as the titular cyborg heroine with Christoph Waltz, Jennifer Connelly and Mahershala Ali in supporting roles.

This visual feast of action and CGI follows Alita, a disembodied “core” who awakens with no memory in a post-apocalyptic world destroyed by a technological fail.

Waltz’s Dr. Ido discovers her and gives her a new body, quickly discovering she is more than what she seems as she goes on to battle other fierce machines.

In the process of auditioning hundreds of girls for the title role, Salazar – who features in Bird Box, Maze Runner and Insurgent – was a clear standout.

“Rosa came in and it was like Sarah Connor walking into the room. She had me in tears, and I was like, ‘wow, that’s amazing. This girl is a leader.’ This is such an important role so she’s got to check all these boxes. She completely blows me away,” Rodriguez recalls.

If Salazar had him at hello, that’s not quite how she remembers it. “I walked into a waiting room at the Four Seasons in LA and it’s like every actress of every age and ethnicity that I’ve ever liked on film was there. I was like, ‘Oh no! I thought I had it in the bag.’ It was humbling, but I just focused on the work, because that’s what carries you home.”

Christoph Waltz and Rosa Salazar

Meeting Salazar, 33, you immediately notice how her eyes are almost as big as the enhanced CGI peepers of her Alita. “Yeah, I know, people talk about that a lot,” she laughs.

Salazar’s path to Hollywood was not an easy one. Although she’d enjoyed acting at high school in Washington DC, she had no confidence in herself. “After high school I roamed around the US like a vagabond with nowhere to live, bouncing around different states. Sometimes a friend was in a college there or another moved here. But what I was doing, which I wasn’t aware of at the time, was picking up idiosyncratic behaviour, circumstances, places, people, things, weird circumstances that I would find myself in. Adventures. And that was my education for my future job. I just didn’t know that at the time,” says the actress who frequently bartended.

“Along the way there are many angels who come to you and go, ‘Wake up! You’ve got something. Don’t waste it. What’re you gonna bartend? You’re f–ing Alita!’ You know what I mean? So I packed up my dog and my stuff and moved to Harlem in New York and told myself I’m gonna do this.”

In New York she found her passion. “First, you have to admit it: I’m an actor. It’s like saying: I’m an alcoholic. I’m an actor! I admit it. I threw myself at it,” says Salazar, who won early TV roles on American Horror Story and Parenthood.

Her street skills served her well for Alita. “I was a poor girl on the streets, so I will always have my ninja moves,” she laughs. “I trained in TaeKwonDo when I was a child and I’ve always been physical – gymnastics, swimming, dancing, rock climbing, bicycle messaging… But this role is more about acting than movement. How are you going to add and enhance things with crazy fantastical moves and action if you don’t have a story grounded in reality? Because no one’s gonna care.”

Of course Cameron and Rodriquez are counting that audiences care very much in this post #MeToo world.

“Back when Jim got the rights to it in 2003, it was a perfect time for that movie, because a character like that was needed,” says Rodriguez. “It’s always a perfect time for that story. It’s a timeless story, and it’s very timely now. You always need these kinds of stories. Sometimes you even see female characters in a sci-fi or an action film, and it just feels like it’s a male character, and they just made it female without any real true female aspects. But Alita is everyone’s daughter/best friend and she has a powerful message.”

Alita: Battle Angel is in cinemas on February 14.