Frank Miller thought he was on pretty good terms with Jessica Alba.

The actress' performance as Nancy Callahan in the 2005 film adaptation of Miller's singular crime noir comic book "Sin City" had been a key role in Alba's rise to become a Hollywood A-lister. It had also impressed the legendary writer/artist suitably enough to inspire him to create a brand-new storyline following her character further when he and filmmaker Robert Rodriguez reunited nine years later for the sequel "Sin City: A Dame to Kill For," in which he sent Nancy down a significantly bleak path as anguish and a thirst for vengeance threaten to consume the exotic dancer following the death of her beloved protector Hartigan (Bruce Willis) in the first film's adaptation of "That Yellow Bastard."

It's juicy stuff for an actor, and Miller was looking forward to reuniting with Alba on set when he rejoined Rodriguez as the new film's co-director. "When Jessica first showed up, I hadn't seen her in eight years, so I went up and gave her a hug and said hi," recalled Miller, who received merely a somber "Hello" in return. "I thought, 'What did I do to piss her off?'

"I realized she was already in her part," chuckled Miller. "She was already ready for a very compelling graveyard scene. Jessica really made an amazing leap between movies in terms of what she was willing to bring to bear and the absolute ruthless discipline she brought to the part. The sense of menace she was able to portray was something we never ever had a chance to do before. It was pretty astonishing."

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Alba admits she returned to the role of Nancy from an entirely different perspective. The character, of course, had changed dramatically. "The love of her life is gone," she said. "She's devastated. She's an alcoholic. She's still dancing. She's not happy about it." But Alba, 33, had undergone her own transformation as well. On the first film, "I was so young, and I wasn't really comfortable in my own skin," she revealed. "Being on a stage and dancing, it was all kind of terrifying to me. I didn't want to be make a misstep. I knew how incredible this world was, and I just didn't want to disappoint them -- or myself."

"In this one, I felt just more confident," she explained. "I feel like if I'm going to be blessed with this career and be able to do movies, I might as well go 150 percent and really push it and be fearless, so that's kind of the attitude that I took... It was cool to be able to take someone from this sweet, innocent, naïve victim to this very powerful warrior who takes her life in her own hands and gets revenge."

"I'm always trying to work with Jessica -- she's awesome," said Alba's longtime collaborator Rodriguez. "She's in my 'Machete' movies, my 'Spy Kids' movies -- I'm trying to put her in every franchise that I have, because then there will be multiple movies." The filmmaker admits he had a sense that she might be a star in the making when he first met her. "She first auditioned for me when she was 17. She was too young for the movie I was doing, but I kept my eye on her because she was one of the few Latin actresses trying to break through. I encouraged her and said, 'Keep going! Keep going!'" Eventually Alba landed her breakthrough role when filmmaker James Cameron cast her as the lead of his sci-fi series "Dark Angel," which brought her acclaim and earned her a Golden Globe nomination, and through Rodriguez's friendship with Cameron, she'd remained in his orbit. "We'd seen each other over the years and say, 'We have to work together some day. And when it came time for 'Sin City,' [I] met with her, and there she was."

Alba pointed out that initially Rodriguez could not envision her as Nancy, finding her too tough, lacking the sweeter, more innocent side of Miller's creation, who was working her way through school as a stripper. "It was hard to find anyone to be like the Nancy in the book," Rodriguez recalled. "If you look at the Nancy in the book, it was a very difficult character to figure out because we were trying to be one-to-one of what the book was. That was the character I just could not figure out."

The filmmaker auditioned Alba anyway and soon found himself moved to alter the character somewhat -- a rare deviation from Miller's template -- scaling back Nancy's explicit nudity and overtly fetishized persona. "Frank drew these never to be movies -- I mean, that was the whole point. 'I'm going to make a book that can never be made into a film,'" Rodriguez said. "So some things we had to adapt. You couldn't even find an actress that you wanted at the caliber that would even consider doing that, because she was just walking around topless all the time, even when she wasn't dancing. It was very stylized in that way, and I knew Jessica wouldn't do topless. But the hard thing was, 'Well, I can either get someone that looks just like the book but can't act like Jessica, or I can get Jessica and we just cover her up.'

"I knew I liked her, and I wanted to work with her, so I went, 'You know what? You're just going to have to create a Nancy,'" Rodriguez continued, pointing out that Alba's innate sex appeal shone through regardless of how much of her body she actually bared. "People to this day still think she was naked because she does it so sexy, and some things are exposed. They ask her about the nudity all the time in the first one, where there wasn't any nudity! It's all in your minds. We can suggest a lot with costume and with attitude."

Miller was sold as soon as he saw Alba take the stage in Nancy's signature cowboy chaps. "What Jessica brought right away was pretty astonishing, because I picked an Emmylou Harris song that I really liked for her to work off," he recalled. "She came out with a lasso, danced across the stage and I was seeing a dream come true. I could not keep my eyes dry. I mean, it made me weep! She finished the dance, and everyone stood there in utter, stony silence. Jessica jumped off the stage and said [disappointed], 'Well, I went over big.' And I had to follow her out and say, 'No -- they were speechless.' Because from the beginning, she was that good."

The artist also concedes that Alba's incarnation of his character not only inspired him to carry Nancy's story forward for the sequel, it also significantly influenced how he would depict her as the character's tale unfolded. "It's one thing to be sitting at a drawing board, alone in your home and coming up with a fantasy character and drawing her whichever way you feel like drawing that day," he said. "And then, dealing with a real performer, -- all of a sudden, things change. It's amazing in working with actors how much I learn from them, and how many new lines will come to mind because of their personality or their strengths, and in Jessica's case, no worries. I was thrilled."

The movie's final story, titled "Nancy's Last Dance," follows Nancy's descent into alcoholism in the wake of Hartigan's death, as the urge for vengeance overwhelms her. "She had been the abused victim, she'd been through the wringer, and she had ended up as many women in her situation, do which is an exotic dancer," explained Miller. "And this time, she turns into something else."

Prepared for Rodriguez's now well-established maverick, outside-the-Hollywood-system approach to making movies, Alba made sure to do plenty of preparation beforehand. "I knew Robert was going to call me on Monday and ask me to show up on Thursday, and I wasn't going to have any time to prepare," she chuckled. "He calls me up and he's like, 'Um, can you come shoot this little thing?' And I'm like, 'Okay. What is it?' He's like, 'Well, it's just this little movie. Just come down. It'll be fun, just a couple of days. We'll shoot you out.' That's just what he does, and I'm there. I show up every time, because it's so inspiring to be in his world and to be submerged in his universe."

Before being summoned to Austin to shoot, she immersed herself in the script. "I saw that I'm in throughout, in all these scripts, all these dance sequences, and she's in disguises. So I'm like, 'Okay -- I have to learn to dance! This is going to be great!'" Alba said. "I worked with a choreographer and I put together the costumes and wigs and all this stuff, so I was prepared. And then I worked with an acting coach to kind of get into that headspace. I'm a mom. I have two kids. I run a company. I'm not, like, this drunk stripper!"

"It's completely different than 'Sin City 1,' what she does here, and she arrived with a lot of that," Rodriguez said. "She arrived with so much of it worked out that it raised the bar. She's the first character we shot in 'Sin City 2,' and it raised the bar on all the actors that were going to come after that."

With Nancy's wardrobe expanding far beyond her famous cowgirl getup, Alba also hunkered down with Nina Proctor, Rodriguez's longtime costume designer, to concoct various looks for her many dance sequences as well as her more incognito off-stage excursions. "I pulled together a bunch of things and she pulled together a bunch of things and we threw them all together in a pile on the ground," said the actress. "I had wigs, I was trying things on -- we figured it out together and we created it together. I really wanted each costume to reflect what was happening to Nancy emotionally at that point, so [her character evolution] made sense... You guys see just like a tiny little piece of it, but I think it was enough."

"Nobody ever looked so good with scars, I'll tell you that," grinned Miller, thinking of the darkest incarnation of Nancy that emerges in the film. And he admits that the effect of the merging of the character he first envisioned and Alba's portrayal has been nothing less than muse-like. "I've already got her next chapter planned."