What’s more humiliating than being kidnapped, drugged, beaten, chased around the four deserted floors of an office parking block by a psychopathic security guard, and partially submerged in an elevator full of icy water? Answer: doing it all in a skin-tight cleavage-hugging evening dress. For Rachel Nichols, the 28-year-old star of the horror movie P2 (about a businesswoman trapped in an underground car park where she’s chased by a psychopath), it could have been a lot worse.

“The wardrobe was a huge debate on this movie,” says Nichols, a Columbia University graduate. “When I read the script originally, it wasn’t a dress, it was a small nightgown with no bra or underwear. Then I read the first scene where she gets wet, and I went: ‘OK, this has got to be altered!’” An emergency meeting with the creative team followed, and Nichols settled for the Marilyn-era figure-hugger instead. “Since I saved most of my body parts from being exposed, I was happy with the compromise,” she says.

That this former TV actress already has the clout to alter screen-plays is a testament to her vertiginous ascent. This year alone she has bagged starring roles in two of Hollywood’s forthcoming blockbusters – the latest Star Trek movie, and the big-budget version of GI Joe. In the latter, Nichols will star as Scarlett, a weapons expert with a penchant for crossbows, skin-tight costumes (this time with stick-on body armour), and knocking the lights out of Sienna Miller, here playing her lethal nemesis the Baroness.

“I would totally beat Sienna in a real fight,” she says. “She’s quite a scrapper, and she’s got some moves, but I’ve been training extensively, and long before her.”

Yet Nichols has been on the brink of success before and is philosophical about it. In 2006 she co-starred in the popular TV show Alias, as a whipsmart protégée of the superspy protagonist Jennifer Garner. There she was groomed by the show’s creator, J. J. Abrams, to take over from Garner, who was then pregnant. The series, however, was cancelled and Nichols’s hopes were disappointed. “I think everybody knew that the show wouldn’t work without Jennifer. But still, they were grooming me, so it was heartbreaking when it happened.”

Nichols is not your typical fame-hungry Hollywood starlet. As the elder of two children born to a schoolteacher father and fund-raising mother in Augusta, Maine, her ambition was an Ivy League education, which she achieved (she’s an economics graduate) and a career as a Wall Street analyst. That plan was hijacked when, during a college lunchbreak, she was spotted by a modelling agent and invited to Paris. She earned the rest of her tuition fees under the catwalk lights.

She says that she doesn’t fear the pejorative model-turned-actress tag. “I was certainly never a Cindy Crawford or a Gisele,” she says. “So I didn’t have to worry about that level of recognition. And learning about photography helped a lot when I started working here in LA.”

She adds that she’s still stunned by her career rise, from bit-part TV roles (first in Sex and the City) to Blist horror flicks such as The Amityville Horror remake and The Woods, to a starring role on the hottest tickets in town. The Star Trek movie in particular (directed by her old Alias mentor Abrams) is so high-profile and top-secret that she can say nothing about it, other than: “They’ve done a very good job in keeping the character I play under wraps. All I can say is that it’s a memorable role.”

Yet there remains a small part of her, she says, that’s waiting for the reality check. “I’ve been waiting for the other shoe to fall for years now, but my good fortune seems to be helped by the fact that I work very hard.” In the meantime she’s living it up in LA, having “cheeky lunches with wine and girlfriends” and enjoying her engagement to a fiancé whose identity remains a secret. “He’s a really handsome boy and that’s all you need to know,” she says, giggling coyly. “[GI Joe director] Stephen Sommers says I shouldn’t mention it because a married Scarlett is not a hot Scarlett.”

Unlike many actors, she does not have ambitions to be a writer or a director. “Unless I’m struck by lightning, you won’t see me foray into other realms,” she says. “I’m having a fantastic time. It’s simultaneously exciting and petrifying. God, life is good.”

P2 is out on May 2 2008

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