Merritt Wever, Nurse Jackie

Season 1 of Nurse Jackie focused on the wreckage of Jackie's personal life. But in Season 2, there's plenty of mess to go around.

"I think, for all the characters, the writers laid great foundations for them last year," says Merritt Wever, whose quirky nurse Zoey is one of the characters who will grab more attention. "For everybody this season, you're just learning a lot more about who they are specifically."

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For Zoey, that means no longer only playing Jackie's lovable sidekick. "Zoey is no longer brand-spankin' new, so she's a little more comfortable in her surroundings," Wever says. "She's still gung-ho and enthusiastic, but she's not as green anymore. She gets to take on more responsibility in the hospital. She gets to do a little bit more on her own, and she's just more comfortable."

Something that hasn't changed: her adoration for Jackie (Edie Falco), despite learning of her affair with Eddie (Paul Schulze). "I think she still thinks that Jackie is the best and the brightest." Wever says. "I don't think you are always so clear exactly how much Zoey knows about people. But she is observant, and I think you never know what's going to come out of her mouth."

Zoey remains one of the characters who doesn't battle many demons. Jackie pops pills and cheats on her husband. Dr. Cooper (Peter Facinelli) inappropriately grabs women when he gets nervous.

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But Zoey does have problems with men. She not only juggles an off-screen suitor in Season 2, but also deals with a colleague who has a crush on her. "There's a guy that comes around the hospital that is a little interested in Zoey," Wever says. "So you get to see her interact in that kind of way for the first time."

Also be on the lookout for Zoey bending the rules a bit more, especially when she mixes it up with guest star Julia Ormond. "I really liked what the writers had me do with her," Wever says. "I'm always shocked and greatly pleased by what the writers come up with [for] Zoey to do — just the sheer balls. Zoey tries to do some covert operations. Even though she doesn't really succeed, I think she can break the rules as well as other people."

Nurse Jackie's second season debuts Monday at 10/9c on Showtime. Season 1 is currently available on DVD.