Kate Beckinsale can compete with the best female action stars today, but the brunette bombshell still had something to prove to writer Greg Rucka when it came to her role in the adaptation of his celebrated graphic novel “Whiteout.”

Rucka’s original graphic novel, co-created with artist Steve Lieber, follows U.S. Marshal Carrie Stetko, who tracks a killer into Antarctica and must solve the murder mystery before the region is plunged into darkness for six months. The film, currently slated for a September 2009 release, features Beckinsale prominently as the gritty, tough-as-nails Stetko — a character Rucka didn’t initially think she could play.

“It’s weird. A lot of people on the message boards and people emailing me were going, ‘Kate Beckinsale? She’s too pretty to be Carrie,’” the writer recalled. “I got to visit the set twice … and the first time was pretty much devoted to seeing Kate Beckinsale and going ‘Wow. How do they make them that pretty?’”

His astonishment, coupled with fan apprehension regarding the casting, had Rucka admitting some initial uncertainty about the casting — but he told MTV she won him over soon enough.

“The first time I walked on the set I saw her wearing the wig, and she had on a little hat and they’re doing a scene that takes place at Russian base in Antarctica,” explained Rucka. “She was Kate Beckinsale — she’s astonishingly pretty aside from being astonishingly talented — but somehow she really looked like Carrie,” he said. “She was Carrie.”