The hard-hitting and emotional NBC drama Law & Order: Special Victims Unit has been known to have a great line-up of guest stars, and its Season 12 premiere is no exception. When a foster couple, played by Joan Cusack and Peter Strauss, call Detectives Olivia Benson (Mariska Hargitay) and Eliot Stabler (Christopher Meloni) to the scene of the crime when their 10-year-old adopted daughter disappears, it soon comes to light that she ran away to meet with a man named Erik Weber (Henry Ian Cusick), whom she met on the internet. Suspected of ulterior motives regarding the girl, Weber denies any wrongdoing, quickly becomes attracted to Detective Benson and even tries to help them out on a case.

To promote his guest-starring arc on the long-running series, Lost star Henry Ian Cusick talked about wanting to distance himself from Desmond, the challenges of playing this role and working with such a talented team of people. Check out what he had to say after the jump:

Question: How would you describe your character, Erik Weber? What do you think makes him tick and what will his motivations be in these two episodes?

Henry: He’s a graphic designer, who you meet very early on in the episode, and he’s very quickly taken with Mariska Hargitay’s character and tries to help them out on a case.

How do your character and Olivia Benson become involved in these episodes? Is he really into her romantically, or is there an ulterior motive there?

Henry: Very early on in the episode you see Benson and my character, Erik Weber, who is a graphic artist. They meet and there’s a bit of flirtation. Certainly from Erik Weber’s point of view, he’s very interested in Benson, and it becomes a bit of a rivalry between Stabler and Weber. There’s definitely a strong interest.

After being on such a hugely successful, long-running show, was it important for you to get right back into TV right away? And, what was it specifically about SVU and this very difficult role that attracted you?

Henry: I was looking to get back into TV as quickly as possible. I wanted to get away from Desmond. It just seemed that I was no longer Ian Cusick, I was Desmond, so I wanted to just shed that skin. And then, when I met (executive producer) Neal Baer and he called me into his office, I was very charmed by him and his idea for the character. Just in talking to him and the writer, I was really sold. It was as simple as that. I liked them, I liked their idea and it just seemed like this would be a really cool thing to get involved with, so I went for it.

Law & Order has an incredibly long lists of really illustrious guest stars, some of which have gone on to win Emmy’s for their work. The show is also like an American institution. How does it feel to be a part of that? Were you a fan of the show prior to this?

Henry: I felt very honored, even just when I met Neal and he told me about the character and I got very excited about it. Coming off a show like Lost, there were other offers, but it was difficult to get excited about anything because Lost was such a great piece of writing and such a hit show. But, I felt I had an input into this character and I knew who I was going to be working with. I got very excited as well by the guest stars involved in the show, Joan Cusack and Peter Strauss. I’m a big fan of both of theirs. So, I felt very honored to be asked and I find myself in very good company. All around, it was a pretty good thing to do.

It sounds like your character may be a victim of bad decisions, in defending the 10-year-old runaway. What are his motivations and how does he factor into the investigation?

Henry: When you first meet Erik Weber, he is trying to be a good citizen. I don’t want to give away too much, but that really is the way Benson and Erik Weber meet up. He’s trying to help out with the case. It is a case of mistaken motives.

What was the most challenging aspect of playing this role?

Henry: Without giving too much away, there’s a scene that stretched me as an actor, and it comes towards the end of the second  hour. There was a tricky scene there that I had to play that was one of those scenes where I know a lot of actors would prepare, but I just had to give it up and trust in my fellow actors, my director and in the writing, and just let it go. It could have gone either way. I’m hoping it’s okay. It was just one of those things where you say, “I’m going to dive in.”

That was pretty challenging. But, I have to say that Mariska was delightful, super-supportive and very, very helpful to work with, as an actor. It was really surprising. She’s done this role for 12 years now, and she has all the intensity and all the care about doing this role, as if it were the first time. So, kudos to her and to Chris Meloni. They’re so passionate about their show and they’re very proud of it, and you can tell that. You really have to pick up your game when you’re working with them.

You didn’t find any difficulty with jumping into an already established team of actors that has such a tremendous rapport between each other?

Henry: Yes, but I was coming from a show where we were running through the jungle. Even though it was dynamic, the delivery was a little bit slower and a little more thoughtful. Here, the pace of delivery is different. It’s faster and the information is handed over quicker. It’s not so introspective. Also, you’re dealing with New York, which I was surprised is such a noisy city. When you’re filming, you’ve got crowds shouting and the constant beeping of horns. I’ve only got two lines to ADR and I can’t believe I’ve only got two lines because it was such a crowded environment from what I’m used to. When I was filming Lost, we’d be in the jungle. The only thing we had to contend with was the sound of the ocean. That was it, really.

Will your character appear in more than just the two-hour season premiere?

Henry: At the moment, no. I think his story has pretty much been told. But, you never know. There’s always a possibility for any character to come back. I guess that’s the nature of TV.

LAW & ORDER: SPECIAL VICTIMS UNIT returns for Season 12 on NBC on September 22nd