Brothers & Sisters' Walker family is expansive, with the siblings, their significant others and more bringing drama, comedy and intrigue to the fore each week. On Sunday (ABC, 10 pm/ET), a new Walker sibling will add a twist to the mix, arriving after his existence was discovered earlier this season. A product of an affair, Luke Grimes' (All the Boys Love Mandy Lane) edgy Ryan Lafferty lost his mother, and now faces fresh loss when he learns the truth about his past. TVGuide.com sat down with Grimes to find out what's behind the new sib's brooding demeanor, how the family reacts to his arrival and what he thinks of fans' mixed reactions to his casting.
TVGuide.com: Can you tell us about your character, Ryan Lafferty?
Luke Grimes: He goes to the Berklee School of Music. He lived a pretty happy life up until a certain point when his mother died. And then he was very shocked to find out that the father who raised him is not his real father ... and his real, biological father's dead. So he finds out at a late age that he's an orphan. The rug's been pulled out from under him. He's a complicated guy.
TVGuide.com: How is Ryan going to be introduced?
Grimes: With a phone call. He's just gotten to the point where he can't do it on his own anymore, so he reaches out to Nora [Sally Field, the Walkers' widowed matriarch].
TVGuide.com: What will integrating into the Walker family be like? How will the siblings respond?
Grimes: I don't know yet — it's all yet to be written. I'm excited to see what happens next... who he likes, who he doesn't like.
TVGuide.com: There are a lot of theories circulating about your character, including that he used to be a drug dealer. Are we going to learn more about that?
Grimes: I'm not sure if it's going to be brought up. But I know that ... [Ryan] did have a problem with drugs, and I'm sure that that's due to having his mother died.
TVGuide.com: Based on what you've shot so far, what's the dynamic like between Ryan and Nora?
Grimes: There seems to be almost a motherly energy coming from Nora. I don't know if that's something that they're planning on playing up, but I feel like that's the way it's going. Maybe [the writers will] play that out. But I know that because [Ryan's] a complicated guy, because he doesn't know what's going on, he's rejecting that energy at this point. He's pushing away a little bit.
TVGuide.com: Was it intimidating to work with a pro like Sally Field?
Grimes: It's not intimidating working with Sally Field, it's intimidating in the times in between when the camera's actually rolling, when I'm sitting next to Sally Field. I don't know what to say!
TVGuide.com: Rebecca is another character on the show that had a scare over being an illegitimate Walker. Do you know what her dynamic with Ryan will be like, now that she's off the hook for that?
Grimes: It's funny, another interviewer asked me if we're going to have a love connection ... . The only thing I know is that one of the audition scenes they wrote for me was with Rebecca, and it was [our characters] meeting at a coffee shop, where he's asking her about her experience meeting the Walkers.
TVGuide.com: So far it sounds like Ryan is a brooding guy. Are there any light moments for him?
Grimes: Underneath it all, he is a really sweet person, [even after] all he's been through. There is a side that really cares and is honest ... . Something we talked about is the product of environment, maybe he's just in a bad place. He may seem a little messy to the other characters, but I think given what happened to him, [it's normal].
TVGuide.com: Is Ryan sticking around for a while?
Grimes: It depends on how everyone responds to it, and if the audience likes it. I know I have a four-episode guarantee, and after that it's fate.
TVGuide.com: For you personally, what has it been like for you to play this character so far? What has your approach been?
Grimes: I'm just trying to wrap my head around what it would be like, because I grew up with a really great, close-knit family ... What would that be like to lose your mother at such a young age, and find out that your dad is not your dad? Not only that, but I think about how rejected and alienated Ryan must feel from everyone, because he's everyone's mistake. The mom messed up, and he was born, and neither family can see him as a real part of them.
TVGuide.com: There was a lot of public discussion among Brothers & Sisters fans surrounding your casting. Did you come across any of that?
Grimes: My mom was reading all these comments and actually read me one. It causes extra pressure that I didn't need, but she thought it was funny.
TVGuide.com: What was the comment?
Grimes: I think one said, 'He looks like a strung-out Johnny Depp,' and one said 'He must have gotten the part because his parents are rich,' which is ridiculous, because my dad's a pastor and they are not rich. It's all because they wanted other people [in the role]. [Fans are] entitled to their opinions, but I just hope that they enjoy what I'm doing. Getting a show is really exciting, but knowing that there were people who watched it every week who didn't want you on, it can start to mess with your head. So I decided, from now on I'll just do my job and they can blog and do theirs [Laughs].
TVGuide.com: At this juncture of your career, how do you feel about some of the pitfalls of being a young, successful actor in Hollywood?
Grimes: It's been a slow burn for me. I think I'm glad that it didn't happen right away, and that I didn't have money ... . It's good, because now I have a handle on what's important and what's not. Something that's not important is trying to find that spotlight. If it comes, it comes, and you have to deal with it because that's what you signed up for, and you've made yourself public domain... . I don't think you'll see me embarrass myself too much.
Watch full episodes of Brothers & Sisters in our Online Video Guide
Crave TV scoop? E-mail senior editors Matt, Mickey and Tim at email@example.com.