Digital Spy spoke to Adams about working with Anderson, the film's Scientology connections and whether or not Peggy is the story's real master. There's also the small matter of a very big superhero movie: Man of Steel.
What stood out for you about Peggy when you read The Master script for the first time?
"I thought she was a force to be reckoned with. It was an opportunity to get to show two sides of the same person. A very public side which was maternal and the private side which was much more steely."
You worked with Philip Seymour Hoffman recently on Doubt. Did you speak to him beforehand about what to expect when walking onto a Paul Thomas Anderson set?
"I didn't, no. I probably should have, but when I work with a director I really like to just go for the ride and get to know their techniques and their process. I really try not to overthink it, but allow myself to be swept up in it."
Was there anything that surprised you about the way Paul worked?
"I was surprised how funny he was, I was expecting it to be a very serious set. It was very intense and very focused, but Paul also has a fantastic sense of humour, a very, very funny sensibility."
Is Peggy the real master of this story?
"I think the film definitely begs the question. I can't say for certain, but like Philip's character says at the end, 'All men have masters'. I'm sure to some degree Peggy is behind the scenes helping to keep him on the right track, so to speak."
Do you think she's frustrated that she can't seem to exert the same control over Freddie as she can Lancaster?
"No I don't think so. I think she really believes in what her husband is doing, so I think it's more that she would like to help him and she would like him to be a person that could really benefit from the process. He's very dangerous, and if he proves that this process can't heal everybody then it's a danger to them."
How do you feel about this being dubbed a "Scientology" movie when it really seems to offer much more than that?
"I would agree with you, it's about more than that. You sort of have to come to terms with people's perceptions of the film or what they want to talk about, what they caught on to before they saw the film. In the end I think I embraced people talking about it because it's a very special film and I think it brought attention that it might not have had otherwise."
Why do you think The Cause is able to draw so many people in?
"I think people were always thinking that it was a new era, lots of people coming back [from the war] and trying to start over. People looking for a purpose."
How do you approach a scene like the one that involves Freddie seeing a roomful of dancing naked women?
"You really do have to just go along with the process. I'm not the kind of actress who asks a lot of questions of my directors unless it's something I really need to know. I think that ambiguity is beautiful, and I think that as long as I understand the specificity for myself and my character and I can figure that out, it's not important to communicate specifically what thoughts I'm thinking or where I'm coming from.
"Paul's really great with that, he has his own ideas and is specific and wonderful with his direction but he really does allow for his actors to create. Although he does give direction he doesn't over-manipulate a performance."
There's been a lot of Oscar buzz for the movie already, which Joaquin has described as being like a bad-tasting carrot. Having been through Oscar campaigns yourself, can you understand where he's coming from?
"I can't speak for Joaquin, but for me getting nominated for an Academy Award allowed me to have a career. I guess I have a different relationship with it.
"Before Junebug I didn't really have a lot of opportunities, so I'm very grateful to the Academy and for being nominated. It brought a lot of attention to a performance and a film that might not have been seen. It allowed for me to have the career I have, so my relationship is slightly different because of that. I do understand his perspective."
How do you approach something like Man of Steel, which is something totally different to The Master?
"I actually started Man of Steel right after, within a week of stopping The Master so that was very different!"
You didn't bring any of Peggy with you to Lois Lane?!
"No, I don't think so! It was fun. I have to say I've been lucky in that way in that I've been able to go from different films and different genres with different challenges. In a way the intensity of playing Peggy and her nature, it was very nice to go into Man of Steel and something that was really energetic and outgoing. Suddenly I'm hanging on a wire in the middle of Chicago. It was a totally different experience and very fun. I always embrace getting to go from one thing to the next."
The film is about Superman's origins, so does Lois only come into play later in the movie?
"You know what, I can tell you what the script was. I haven't seen the film, I've only seen what everyone else has. I have no idea how it'll all be presented. It's all top secret!"
The trailer looks very different to what you'd expect from Zack Snyder - it almost looks like a Terrence Malick movie?
"I loved it, I absolutely loved it! It made me excited to see the film and I'm in it. Hopefully it's gotten Superman fans excited, too."
Are you signed up for sequels as well?
"I would be more than happy to jump onto a sequel but you've got to, what's the saying, don't put the cart before the horse? Don't count your chickens before they hatch. I always take things one day at a time."
The Master is showing at London's Leicester Square Odeon in 70mm now. It opens wide across the UK on November 16.