Blonde, blue-eyed, and button-nosed, Chloë Grace Moretz doesn't look like a cold-blooded killer—which is exactly why she's so compelling in this month's moody horror remake Let Me In. "My character, Abby, is a vampire," Chloë explains, "and she and this bullied boy fall in love, but it's a twisted relationship. I liken it to Romeo and Juliet." Others will be tempted to compare them to Edward and Bella, but Twi-hards take note: "This movie is deeper and grittier," Chloë says, "and way more realistic." Of course, this isn't the thirteen-year-old star's first trip to the dark side: She played the foul-mouthed, gun-strapped tween Hit-Girl in last spring's cartoonishly violent Kick-Ass. She'll finally lighten up next year in director Martin Scorsese's 3-D adaptation of the best-selling book The Invention of Hugo Cabret, alongside costars Sacha Baron Cohen and Jude Law. Pretty good for a girl who got her start doing print ads in Georgia a little over eight years back. "It's breathtaking to come to this point in my career," Chloë says. She keeps it real by keeping the "regular" teen she calls "home Chloë" (who loves shopping, sleepovers, and ballet) separate from "acting Chloë," the budding movie star, with only one exception: "I love Betsey Johnson dresses," she says, "because after I wear one to a premiere, I can wear it to a friend's Bat Mitzvah."