Well, that was traumatic. While we knew there probably wasn't going to be a happy ending for "Sons of Anarchy" in the sixth season, the death of Dr. Tara Knowles, especially coming in such a violent way at the hands of her mother-in-law, was particularly harsh. And, as Tara's portrayer, the fantastic Maggie Siff, tells Yahoo TV, it sets up what promises to be an unhappy final season for Tara's widower, SAMCRO president Jax Teller.

Series creator Kurt Sutter's "clearly not planning the happily-ever-after ending. I know he wanted to see Jax move into this final chapter stripped of everything," Siff says. "So he's lost his best friend, and he's lost Tara. I think Opie also had a real strong streak of goodness in him, a nobility that Jax clung to. And to see both of those characters lost within a year is brutally hard.

[Related: Kurt Sutter on the 'Sons of Anarchy' Finale: Jax and Tara Are Like Romeo and Juliet]

"Kurt has said he feels like Jax has needed an event like that to finally be [forced] to make a choice. All along, Tara's been the voice saying to him, 'make a choice, make a choice, you need to make a change.' Now, that question is more alive than it's ever been — now that she's dead and he's the sole caretaker for their children."

Siff, who's been with the series since its 2008 premiere, also talked to Yahoo TV about her saddest moment filming the finale, her final performance as Ophelia and Ophelia-like characters, and her impending mommyhood. She also explains how she's looking for her own "Orange Is the New Black" for her "SoA" follow-up.

Obviously, the finale was such a shocker and Tara is a big loss to the show, but we know from talking to you previously that you truly care about the story that's being told as much as you care about being on the show. Is that factoring into how you're feeling after that ending?

Oh, yeah. Honestly, my prevailing feeling is one of, kind of gratitude, and I'm ready to move on to the next thing. I think [the finale] sets up the next season really, really well. And I'm actually very excited to sit back and watch it, which is interesting. I didn't anticipate feeling that way, but when I saw last night's episode, I was like, "Oh, this is really — [Kurt's] doing a really amazing thing here, the way he ends the season for Jax, and the way things get set up with Nero and Gemma — it's going to be awesome!" And I feel proud to be a part of that in whatever way that I am.

Kurt told us he told you about his plans for Tara before the season began, and just given the storyline and the "Hamlet" aspects of the series, it probably is never truly a surprise, but did you think Tara would live at least through part of the final season?

I've never been sure, because she's the Ophelia character. I felt I could go either way. I thought Kurt could create an arc wherein you see Tara really ascend the throne and become Gemma. And I also thought she could go out sort of earlier and more tragically. And I think he sort of did both, a little bit, over the course of those six seasons of me on the show. I think Tara had a tremendous arc, and I knew that that was true from the beginning. I knew she was going to have a really interesting and transformative arc, and I was always really excited about that. So I didn't really ponder it too much, about when the end would come.

[Related: 'Sons of Anarchy's' Katey Sagal: Tara Has Crossed a Line With Gemma]

Speaking of Ophelia, is it true that you have played that character several times?

(Laughing) I've played her twice before. One, it was a professional production I did while I was still in college, over the summer, and then I did it again in my early 20s, both in Philadelphia where I started out my theater career. So yeah, I'm really well acquainted with the play, which has always been fun for me. I've read a lot of Shakespeare, but ["Hamlet" is] one of the few that I can say I know inside and out. But third time is a charm. Never again! ... I'm putting the role to bed. And I'm just too old.

The finale was filled with sad moments and a few that seemed really hopeful for Tara. What was the saddest one for you?

The saddest scene for me was watching the guys say goodbye to each other and knowing that Jax is coming home, what he's coming home to — but that's a personal experience of the show. That was me watching all of these people that I love, have an experience of loss and change, [that] I was also having. It was me watching my friends and having an experience of admiration for all of their incredible work and a feeling of poignancy over it. And I think it was just the leave-taking. I think that's what started to move me, because I've done my own leave-taking with those people.

In terms of working on that episode, I think the hardest scene for me shooting it was the scene in the park, with Jax and the boys. Really trying to live inside of a moment where you think your life is going to end and you've failed, and saying goodbye to your kids and the man that you loved, who's also potentially the person who's going to take you out. I found that scene terribly challenging.

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Tara really had the chance there to really lay out everything for him, why she'd done the things she'd done, what she felt he'd become, why it was so important to her to prevent their sons from following in his footsteps. Do you think she got to say everything she needed to say to him?

Yeah, she did. ... That was such an emotional scene, and it was so hard to kind of work through the emotion to get across the urgency of her point. But she was also in a situation where this is it; she had to say what she had to say. And I was grateful for her [getting] a chance to let him know, and also, in a way, let the audience know just how transformed he had seemed to her in her eyes. How dark he had become to her. And how scary. When she [tells him], "You've become this monster," I mean, that's what's been driving her all season long, in terms of deciding that she needs to get out, and that she's alone, that there's nobody else who's going to help her, including her husband, who in some ways really lost himself in this world, in the culture of violence.

Were you happy they got to reconnect before she died, in the hotel after their meeting with Tyne Patterson?

Yeah, and Jax really steps up and does something very redemptive and noble and responsive to her and their children. He chooses them, in a way, and I think that that's the man that she loves and that's the man that she's always believed in. That's the man she's always believed was there underneath all of this other stuff that's been so terrifying to her. I really wanted it to end on a note like that. I wanted their love to be kind of in place before she went out, because I feel like that's been the beauty and the tragedy of their story together. They're two people who have always seen the most beautiful parts of each other and have needed something in that other person to keep them going. I saw a clip from an episode really early on where he said to her, "You're my way out of here." I think Jax has always seen Tara as his hope for a different kind of life, or a transformation within himself and something that keeps him moving forward. And I think he's always made her feel kind of protected and alive and seen in a way that nobody else has [seen her], because she's a very hidden person. That's the thing that between them has never died, so I didn't want to see her die without feeling they had reclaimed that position with each other.

What's next for you? Obviously being a new mom soon ...

Yes! [The timing] just couldn't be better. I have a little break, and that's definitely my next big project. I'm also helping to develop a little independent film, and that'll hopefully shoot sometime next summer or fall, early fall. So there's lots in front of me that I get to work on, between planning and prepping my mind for motherhood and this other project that I'm excited about. ... I'm due at the end of March, beginning of April, so I'm still in my second trimester and heading into my third. You know, enough time to reorganize my house, and, I don't know, get some diapers.

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Are you open to doing another TV series? Did you like the experience of TV, of getting to really develop a character?

I do. I love the schedule. I love that it's half the year. I love that I get to go back to New York and do theater or film, so I would love to do more of it. I think because I come from the theater, a network schedule would be harder for me, because I kind of feel like the way I found balance is doing this for half the year and then really being able to mix it up for that other half of the year, and stretch other kinds of muscles. But then throw a child into the mix, and I don't know! But that's all to be discovered. And yes, as an actor, it's been so interesting to play somebody over a number of years and to see their slow-burning transformation over time. That's not something you can get anywhere else, and I think it's artistically incredibly exciting.

Do you have a dream role or a kind of character that you would want to play?

I guess — Tara's been such a long, sad, dark ride. I have loved her, and I've loved working on the show. But I would love something that has a little bit more lightness in it. Not a sitcom, but ... I've been watching "Masters of Sex," and I find that role that Lizzy Caplan is playing to be one of the most amazing women I've seen on television. It's so complicated and so nuanced, it's serious, it's funny. ... A lot of the women on "Orange Is the New Black" I feel similarly about. There are a lot of roles out there now for women that are really complicated and rich. I don't think I can say I have a dream role, but I have a dream to land one of those roles.