LOS ANGELES—There are some powerful Hollywood people at the media conference for Transcendence, no question. In the middle, front and centre, you’ve got Johnny Depp, he of the multiple Oscar nominations and worldwide fan worship. Two seats to his right is Kate Mara, who has been a boon to the rise of Netflix with House of Cards and looks set to emerge as one of this generation’s biggest stars, having been cast as Sue Storm in the next Fantastic Four. Between the two of them is Morgan Freeman, who everyone wishes would just give up this acting thing so he could devote himself to narrating their own lives.

So excuse Rebecca Hall if she gets a little lost in the fray. As she’s sitting in the far corner, it can be easy to forget that Hall is the emotional lifeblood of the film they’re all here to promote.

Helmed by veteran cinematographer Wally Pfister (Inception, The Dark Knight) in his directorial debut, Transcendence (now playing) centres on famed computer scientist Will Caster (Depp) and his march to create a fully evolved computer that can process actual human emotions while combining all of humanity’s collective intelligence. It’s kind of like Her, just with much more at stake than Joaquin Phoenix’s feelings.

Hall plays Evelyn Caster, Will’s wife and a computer scientist in her own right. Much of the film relies on her reactions as Will starts to abuse the power of his discovery. Hall understands the emotions that her character encounters. “I’d like to think that, were I in Evelyn‘s shoes, I’d think about the moral ramifications of deciding to maintain my husband in cyberspace,” she says, during the hotel-room gathering. “But those decisions come out of a place of high emotion and grief, so who knows? The line is a bit difficult to draw in that respect.”

The film asks the hard questions about modern technology, and Hall, for one, doesn’t shy away from the scariness of the future and the benefits or otherwise of integrating technology so closely into human life.

“I suppose it’s an interesting thing that the film raises up, because technology is arguably the thing that’s going to get us out of a lot of problems,” Hall says, her English accent resonating through the room, a reminder that she’s a native of London, despite how many Americans she’s played on-screen over the last couple of years.

“It’s probably our greatest hope in terms of solving everything that we find problematic now. But it’s equally likely to throw up a whole world of problems that we have no understanding, perception, or even imagination to anticipate.…So it’s complicated. Whether we like it or not, we’re becoming more and more closely integrated with them [computers], so we have to deal with these problems.”

Because Hall is the centrepiece of the film as the distraught, conflicted wife of Depp’s power-hungry professor, it was important for her to feel comfortable in the role. Having played opposite such names as Ben Affleck, Will Ferrell, and Javier Bardem, Hall was ready for the star power Depp brought, but it helped having a familiar partner behind the camera.

“I worked with Wally when he was a DP [director of photography, on 2008’s The Prestige], and he was incredibly warm and kind to me at a moment when I was particularly frightened and didn’t know what I was doing. So I would have done anything for him,” she says, explaining why she took the role. “But the one thing everyone thinks is ‘Oh, he has all the greenness of a first-time director, so how is he going to deal with the actors?’ But weirdly, a DP observes actors’ work far closer than a lot of people on a set. So he gets it and he knows that and he knew when to stand off and he knew when to be there.”