With "Sex and the City's" Cynthia Nixon winning an Emmy during the recent Creative Arts awards, the "Law & Order" franchise continues to be the perfect place for an actor to play a role against type and reap the rewards. Tonight's 10th season opener of "Law & Order: Special Victims Unit" sees just that as Luke Perry and Sara Gilbert guest star in a volatile case involving rape, child abuse and post-traumatic stress disorder. The two actors, along with executive producer Neal Baer, talked with our Jim Halterman about their trip to the darker side with the long-running procedural.

Though Perry and Gilbert are best known for lighter fare such as "Beverly Hills, 90210" and "Roseanne," respectively, each actor had their reasons for stepping into the heavier world of "Law & Order: Special Victims Unit." Gilbert, who can also be seen on CBS's sitcom "The Big Bang Theory," discussed what drew her to "SVU." "I'm a fan of the show and the writing and the actors so I was excited that they were interested in me to begin with. I always think it's exciting when I get to play a dramatic character and something that I don't always play. People know me more for comedy, I think, so it's always exciting to me when I get to play something so dramatic."

Perry, who also recently completed an episode of CBS's "Criminal Minds," revealed that he found watching Gilbert just as rewarding as his own part. "From what I know of Sara's work," he explained, "we all think she has razor sharp timing, perfect delivery and those are the great tools in comedy. It was great for me to see that she's also has a really deep bag of dramatic stuff that she can do, too. That's always exciting for an actor when you get to work with somebody and you get to see them do something completely different."

Baer chimed in with a warning for viewers to be sure to have tissues handy. "You'll cry when you see Sara and when you see Luke. You'll be shocked. It's really like seeing them both in really interesting roles that are unexpected."

Though not wanting to give any spoilers for the episode, Baer shared that the characters that Perry and Gilbert play will be easily identifiable to viewers. Defending the show by saying that the writers don't simply go to a dark place for the sake of making audiences squirm in their seats, Bear said that "Our show is also about the social issues and the psychological issues so even though [the episodes are] intense there is heart to it. For instance, in Sara's character, she's really suffering because she's lost her child. She's given him up. So people can relate to that and even though it might be psychological challenging or dark, it's not, to me, grim."

Predominantly a comedic actress, Gilbert was asked how she was able to get inside such a dramatic, emotionally tortured character. "I worked with my coach who I love," she shared. "I also talked to a couple of rape victims and one in particular who had had post-traumatic stress disorder to kind of figure out what that's like. She talked about a lot of numbness and stuff so that really helped me understand how it's hard to function and what happens. And then I just tried to think about losing the things that are most important to me. What would make me so disabled that I would start to lose the things in my life that are � that mean something to me."

Perry's character, however, doesn't seem to be quite as sympathetic, though he pontificated on playing a character that some would call a "bad guy." "I don't see [those characters] as plainly bad," he said. "Nobody's bad all the time. Nobody sits around being bad 24/7. So there are always moments when you gotta find the humanity to people who may be considered the bad guy. And this is one of the things about this particular script of 'Law & Order' that, as I read it, at first I saw it in kind of primary colors. And the more I read it the more I started to realize there was so much room in there for me to find places there the guy could be likeable because in his mind he's doing a good thing."

The characters that Perry and Gilbert play have the kind of deep, layered complexity that the show is known for. Baer explained, "What's really interesting about [Luke's] character is he's a really good father and that comes through that he really loves his kid and so it's not just good guys/bad guys. And Sara's character was a good mother and because of the circumstances is no longer a good mother but one will hope she becomes one so it's very complicated."

Speaking about "Law & Order: Special Victims Unit" as a whole, Perry said he admires that the writers "don't just do the victim of the week or bad guy of the week. All this stuff comes back to inform the regular characters and it really keeps that part of the engine of the show running. That's how you get a show that stays on the air for ten years. People care about all that stuff across the board and then they're really smart the way they lay it out there."

Case in point, Gilbert's character ends up having quite an impact on Mariska Hargitay's Detective Olivia Benson. Baer revealed, "What's interesting with Sara's character is she's just physically and emotionally a mess, as you'll see, and Mariska's character feels guilty because she didn't remember at first taking on this case some years ago. And Sara's character is a impetus for Mariska to deal with really dark things in her own life. And so there are scenes with Mariska alone where she flashes back onto some very bad things that happened to her in previous episodes when she was attacked."

Though "Roseanne" and "Beverly Hills, 90210" have both been off the air for many years, Gilbert and Perry are still associated with their early successes and both seem to have come to terms with their respective pasts. In talking about her role of Darlene Connor, for which she received two Emmy nominations, Gilbert said, "I just feel that I'm really honored to have been a part of 'Roseanne' and I know that it's going to be a part of my life forever so it's a waste of time to, you know ... like I just [have] to accept it and I'm proud of it. I 'm honored that I was chosen to be a part of it."

Luke's past on "Beverly Hills, 90210" has come up more recently with the new "90210" version on the CW network. With former cast member Jennie Garth appearing as Kelly Taylor, it was revealed with last week's episode that Dylan (Perry's character) is the father of her four-year-old child. Though Perry gave a definite "No" in terms of returning to the Beverly Hills zip code, he does not seem bitter about the success. "What I have determined is that stuff doesn't happen by accident. We put a lot of hard work into it and so do a lot of writers and directors. And when shows take off and they sort of become part of the American psyche like that there's a time when it's happening that you're a little resentful for it because you had no idea it could possibly get that big but when you stop and look at the whole picture of your life,... from that perspective, I'm very proud of it. It was a lot of fun. It gives you a neat relationship with the American public."

With both Luke and Sara having experience in roles that exhibit both comedic and dramatic sides to them, do they have a broad design to their careers to make sure both sides are being serviced? Perry felt that actors in general, "are always looking for good parts... and we don't necessarily look for a good comedic part and we don't necessarily look for a good dramatic part. What happens many times is you find parts that what you bring to the role really services it well. In the instance of Sara, you take a good part and you make it a great part by the way that you execute it. On 'Roseanne,' she was written as one of a number of children in this household and two seasons into that show Sara is the go-to girl for the funny because she's bang right there with it. But as an actor you can't be that selective and try to do that. I just look for a good part."

The 10th season opener of "Law & Order: Special Victims Unit" airs tonight on NBC at 10:00/9:00c.