"I had to take that nervousness and just eat it," she said. "Dejah - she's not nervous. There's no nerves."
"She's a strong warring woman who can kick anyone's ass - and yet you start to see her become accessible, open and vulnerable to love," Collins said. "That journey is one I myself have taken. It was a pleasure to say, 'You've done this before, now do it big-scale for everybody.'"
Collins, 34, was born in Houston, Texas, but it would be easy to think she's British, because she talks like one both as Dejah Thoris and in her first star-making role as Portia in a 2004 movie version of "The Merchant of Venice," with Al Pacino as Shylock. She also played Kayla Silverfox, the mind-bending love of Hugh Jackman, in "X-Men Origins: Wolverine," and had a recurring role on the first season of "True Blood."
Collins was a natural in the fight scenes. She claims to be a black belt in shitō-ryū, a form of karate, and learned about samurai swords from her father. "The samurai say their soul is in the sword," Collins said. "The marriage of the body and the metal, to me, was incredibly invigorating."
A harder challenge was acting opposite Willem Dafoe, who portrays Tars Tarkas, leader of the nine-foot nomadic Martian creatures called Tharks. On set in London, and on location in Utah, Dafoe would act in a motion-capture suit (so his computer-generated character could be filled in later) sometimes wearing stilts, sometimes holding a foam-rubber Thark head on a stick.
"Willem is a force of nature, and one of our greatest actors," Collins said. Sometimes, when Dafoe was using the head-on-a-stick, Collins would deliver her lines not looking at the foam-rubber head but at Dafoe ruining the take.
"I said, 'Willem, you are so engaging and incredible, I can't not look at you,'" Collins recalled. "He said, 'You'd better try.' So I finally did it. We only had two takes of me doing it."
If "John Carter" is a hit, Collins looks forward to a sequel. "Of course, their love story is going to expand," Collins said of Dejah Thoris' relationship to John Carter. "I would like to see them delve into: What is this Issus, their religion? Where is her mother? Why hasn't she ever been with a man? ... We'll definitely find out."
One thing's for sure, Collins said: "Believe you me, if [part 2 and part 3 are] made, I gotta keep working out."
For a view from the set of "John Carter," and a look at the Utah connection, read The Cricket's article from Sunday's Tribune. Also, read this story about how the film moved from the page to the screen.