'Castle': Lisa Edelstein on Her 'Fun' Season 6 Arc and Playing Beckett's Mentor

Lisa Edelstein continues to make the rounds on the small screen. Her latest stop: ABC's Castle.

Edelstein's character, the tough and highly skilled federal investigator Rachel McCord, plays a crucial role in determining the future of NYPD detective Kate Beckett (Stana Katic) and crime novelist Richard Castle (Nathan Fillion). In the season-five finale, Beckett was toying with relocating to Washington, D.C., to work on a task force at the U.S. attorney general's office, a dilemma complicated by Castle's proposal of marriage. First appearing in the sixth-season premiere, McCord represents someone "Beckett would like to emulate," Edelstein tells The Hollywood Reporter, adding that McCord's journey is "a really fun arc on the show." (Watch a preview from Monday's season-six premiere above.)

But don't expect catfights or sparring between McCord and Beckett, who have what Edelstein describes as "a business relationship." Says Edelstein, "McCord is really a mentor for Beckett and is trying to show her how to further her career. They have a mutual respect for each other. They like each other a lot. McCord is really there to push Beckett to be better."

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So much so that Beckett has the desire for "the kind of career that McCord has," Edelstein hints. Whether Beckett is successful is a question that unfolds as the season progresses.

Edelstein later reaffirmed the pair's dynamic, saying: "This isn't about two women going at each other or competing or anything. This truly is a friendship." As time goes on, not all will be marshmallows and rainbows: "That friendship gets tested."

Edelstein reveals that McCord interacts with nearly all of the regulars on Castle — minus Castle's family. "I just saw them on set," she says, laughing.

After a seven-season stint as Dr. Lisa Cuddy on House, the actress has dropped by numerous TV shows including The Good Wife, Elementary, Scandal and House of Lies — and booked the lead in Bravo's Marti Noxon pilot. Edelstein notes that the Castle gig was enticing, mainly because of her mother's love for the cop procedural. "My mother was extremely excited about the idea," she said with a laugh. "Sometimes you have to do what your mother wants you to do."

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McCord, however, is "very different" from Cuddy, Edelstein insists: "[McCord] is tough. She's in a man's world, and so she has to behave accordingly. She loves what she does and she's very passionate about it. She's a very different person than what Cuddy was. Cuddy had similar characteristics but in a very different way."

As for her favorite scene? "It's not until the third episode," Edelstein teases. "I'm not sure if it'll be my favorite scene when I see it, but it was my favorite scene to shoot."

Though currently she is slated to appear in just three episodes, her future is left open-ended. "McCord is not dead at the end, so on that note she's still alive," Edelstein says. "She still exists in that world."

Castle premieres Monday at 10 p.m. on ABC.

E-mail: Philiana.Ng@THR.com
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