Bella Maffia: Nip/Tuck's Roma Maffia takes center stage with a harrowing pregnancy for her lesbian character, Liz Cruz.

"She's the voice of reason," says Roma Maffia of Liz Cruz, the pragmatic lesbian anesthesiologist she plays on Nip/Tuck, FX's lilt show about two Miami plastic surgeons constantly stuck in one (a)moral dilemma after another. "She's the most comfortable with herself," Maffia continues. "She's not emotionally or sexually attached to [the doctors]. She can just say [the truth]."

Initially a recurring character, Liz was brought on as a regular for the second season (concluding October 5). But not until she decided to have a baby did Liz come front and center. Using sperm donated by rakish surgeon Christian Troy (Julian McMahon, Maffia's old costar from NBC's Profiler), Liz did conceive--but ended the pregnancy after learning the baby would have Down syndrome.

"I was really stunned," says Maffia, who learned of the plot twist only when she read the script. "I thought it showed a real different color to Liz. She felt she didn't, have the capabilities to mother a child that would've been so challenging. For me, where I would think Liz is [in her life], that's very surprising. But, you know, it made sense. It opened her up. It made her more dimensional to me."

Fans of Nip/Tuck know this is but one of many envelope-pushing elements to the show, as out creator Ryan Murphy (Popular) takes full advantage of FX's desire to be basic cable's answer to HBO and Showtime. For instance, there's enough bed-hopping to shame the cast of Melrose Place, but Maffia thinks it's all in service of the show's larger themes.

"I think [the show] does open up the question 'What is sexuality?'" Maffia says. "What does it mean, 'sexuality'? What does that look like, and who do we expect it from?" Asked about her own sexuality, Maffia jokes, "I went to Catholic school, and they taught us I had no sexuality," before saying she's straight.

Although Liz is now single, Maffia is confident she won't be that way permanently, "because one of the things that Liz is ilk pursuit of is love." Besides, Maffia brags, "Liz looks damn good. I mean, Liz wears more makeup than I wear!"