The CW's Smallville (Thursdays at 8 pm/ET) ups its "hot alien" quotient this week with the arrival of Clark's interstellar (and interminably sexy) cousin, Kara, aka Supergirl. Filling the comely Kryptonian's standard attire of "half-tops and short shorts," as she puts it, is Laura Vandervoort, a Canadian knockout with a hefty resume up North. "I started acting at 13," she says. "And did a lot of shows in [Canada]," including Goosebumps, Are You Afraid of the Dark.

Vandervoort also did a guest spot on CSI last season, but it was her super debut at this summer's fanboy-packed Comic-Con that really put her face out there. Way out there. "I was worried that I wouldn't be accepted because the cast has been together for six years and here I am, the newcomer. But when I got there, everyone was great… they freaked out about Erica [Durance] and Justin [Hartley]. That was intense!"

Just as intense is her workload, which includes not just the rigorous Smallville shooting schedule in Vancouver, but also frequent trips to Toronto for the N's Instant Star, where she costars as Jude's sister Sadie.

And on top of all that, there's also the research required of every new superhero. "Not gonna lie, I've watched the show before…. Tom is very nice to look at, so I enjoyed the show!" she says. "I watched the first season, but then got really busy acting myself and I was going to university. Now I'm catching up with the DVDs… and anytime there's a comic-book store [nearby], I'm walking in there picking up new comic books."

This being Smallville, however, the effort she's putting into building Kara's backstory doesn't touch the hard work that goes into her present storyline. "The first day, they had me in a harness, testing my ability to stay balanced, [and then we worked on] landing, taking off, spinning around, all of that. I've gotten used to it and I'm having a lot of fun now," Vandervoort happily reports. "I'm doing a lot of my own stunts and I'm doing fight sequences."

Fighting, already? "Obviously, she's not from this planet, so she's not familiar with the etiquettes of Earth," laughs Vandervoort, adding that the women of Smallville had better watch out. "The first time she meets Lois, she's not sure who she is and Kara sees her as a threat… their first encounter is basically me throwing Lois around the woods."

For those of you who love that sort of action (and really, who doesn't?), the actress suggests setting your TiVos. "There's more to come… a lot of girl fights coming up!" Kara — who has been in suspended animation since her spaceship crashed on Earth — also brings with her a density of information for Clark regarding his origins. "She tells [him] a lot about his home that he doesn't know about, because on Krypton she was older than he is.… In fact, Kara was there when his mother was pregnant with him and vowed to look after him if anything went wrong," she explains with the clarity of a bona fide fangirl. "When I get to Earth, he's older than me and the dynamic is pretty cool because it's a constant battle… he tries to be the 'big' brother."

And while one could expect talk of a possible spin-off if the character, um, takes off, Vandervoort is quick to point out that it all depends on the folks with the real superpowers. "It's up to the producers and the viewers, I guess. When the shows start airing, they'll probably go by the feedback to see what they want to do with me, if they want me to stay on Smallville… or if they even want me around at all!"

Hmmm, a hot blonde who can fly and hold her own with Lois Lane? We're guessing this one is going to win fans faster than a speeding bullet.

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