When Kaitlin Cooper dropped by Newport Beach in a few eppies of The O.C. last season, we were amazed at how much the she reminded us of her big sis, Marisa. (She truly is Mini Coop!) But now that Marissa is gone (tear), someone's gotta take her place as The O.C.'s resident wild child -- and who better to do that than Kaitlin herself, Willa Holland. Before her big premiere as a series regular, we sat down with this former Alloy It Chick to talk about her new life on The O.C. Is Willa really the bad girl she plays on TV? More like Summer and Seth's love child! By Rebecca Silverstein.

So give us the dirt -- what can we expect from Kaitlin this season? Any chance of her calming down?
No, not really. I can't give anything away because Josh Schwartz will kill me if I do. But she has a love interest, and she's definitely living up to her reputation.

When did you find out you were gonna come back?
I found out three days before my 15th birthday -- it was a pretty good birthday present.

Did you know that Mischa Barton wasn't coming back to the show?
I had absolutely no clue. I didn't know until I actually walked into the set [to film this season]. In the last script [from last season], they didn't give out the last couple of pages, so we knew something big was gonna happen, but anybody who didn't actually work in [those scenes] didn't know. I would ask Josh everyday, "What's happening, what's happening, what's happening?" And he was like, "Ahh, get away from me!"