Jessica Alba has revealed how she got in touch with the dark side for her return to Sin City.
The Fantastic Four and Dark Angel star is reprising her role as exotic dancer and revenge seeker Nancy Callahan in Sin City: A Dame To Kill For, a prequel to the 2005 graphic novel adaptation Sin City.
"I just really connected with the dark side of Nancy," the actress told the crowds at Comic-Con.
"It was hard to detach from that until the movie was over," she added.
Frank Miller, the film's co-director and graphic novel creator, didn't initially understand the effect that returning to the role had on his leading lady's personality.
"I haven't seen her in eight years, how did I p*** her off?" he joked.
The 33-year-old actress said she worked with an acting coach and choreographer before production, which was full of special effects and mostly shot in front of green screens.
"The second time, I felt comfortable. I felt like a woman," she said.
Jessica - who shared photos of the San Diego convention, which she dubbed "Best day" on Twitter - was joined at the panel with her Sin City co-stars Josh Brolin and Rosario Dawson, as well as co-directors Frank and Robert Rodriguez.