Grey's Anatomy Newcomer Kelly McCreary: Maggie and Meredith Are Like "Oil and Water"

Grey's Anatomy's newest surgeon, Dr. Maggie Pierce (Kelly McCreary), has been welcomed to Grey Sloan Memorial with not quite open arms on the part of her (unwitting) half-sister, Meredith Grey (Ellen Pompeo). And the dislike is becoming mutual, as viewers saw at the end of last week's episode.

"They're like oil and water," McCreary tells TVGuide.com. "It's a little bit of a heartbreak for [Maggie] to discover that her sister is not somebody that she really wants to know, in spite of the fact that she came all this way to find out."

On Thursday's episode, Maggie tries to bond with her other new coworkers — and she doesn't exactly have an easy time of it. Will she ever find out that Richard (James Pickens Jr.) is her father? And how long will they be able to keep Meredith in the dark? Check out our full Q&A with McCreary to get her take on what's ahead for Maggie:

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TVGuide.com: So, Maggie finds it difficult to fit in with the other doctors this week?
McCreary: It's really kind of comical, actually. It's a sort of day in the life of a person who is really trying hard to demonstrate what a great doctor she is and make an effort to connect with her colleagues, and she just time and again is putting her foot in her mouth or saying or doing the wrong thing. I think people will relate to the awkwardness of being the new kid at school. There are some really, really funny moments.

Is there anyone at Grey Sloan she does become close with?
McCreary: She and Bailey have in common their interest in the genome lab. And Richard has already become a confidante. ... So, she'll keep connecting with those two. She's got a new intern in Jo. They spend a lot of time together. Whether or not they become friendly will sort of be up in the air, but we'll find out. It's definitely a teacher-student mentorship kind of relationship more than a friendship. But Maggie has a lot to offer, so it's just a question of whether Jo can receive it and work hard enough to receive it.

How long is she going to be able to hold onto her secret about Meredith?
McCreary: She doesn't even really want to know Meredith at this point. They just don't get along. ... Under the circumstances, I think it'll take some kind of reconciliation between the two of them before Maggie can get to the point where she is willing to open up like that.

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Does Maggie struggle with not really liking Meredith and not wanting her to be a part of her life, but also wanting to know more about her mother  and knowing that Meredith's maybe the only person who can provide that information?
McCreary: Exactly. That's exactly the tension. She's come all the way across country, left her home and family whom she loves dearly, on this quest to find out about her mother. So, yeah. Obviously she's going to have to make some connection somewhere with Meredith for her trip not to be in vain, for the change in her life to be worthwhile.

Much of what viewers know about Ellis isn't exactly positive. How much can we assume Maggie knows about her mother?
McCreary: I suspect once she knew who her mother was, a Google search would tell her all she needed to know about [Ellis'] professional life and accomplishments. But I think the whole parentage is completely shrouded in mystery for her. I think she has no expectation of learning about how, I guess challenging, we'll say, Ellis Grey might be. I don't think she has much expectation of anything at all. It's a complete mystery and that's why she's there, because it's a part of her that is just a total enigma.

She also has no idea Richard is her father. Did she really mean it when she told him she didn't want any other new relatives in her life?
McCreary: I think she's protecting herself. I think she's trying to talk herself into letting go of the idea of getting close to Meredith or finding out about Ellis through Meredith. ... She and Richard will find that they have something in common early on in the next episode. It's a fun little moment. The audience will definitely pick up on some family resemblances.

Will we learn anything about Maggie's adopted parents?
McCreary: I really hope so. The relationship with her adopted parents will be discussed and dealt with a bit in some really fun ways, but we won't meet them just yet. I don't know when that'll happen.

What else should fans know about Maggie?
McCreary: I think one of the most fun things to play is this tension between having this really, really great family — they treat her well, she treats them well., they love each other very much, they have a good time together  —  and still feeling like something's missing, like that's not quite enough. That's what's really compelling to me about Maggie: that sort of dark underbelly of this person who seems to really have it all together.

Grey's Anatomy airs Thursdays at 8/7c on ABC. What do you think of Maggie's character?