I'm truly grateful to the writers of Fringe for giving me that because, over the years, when I've spoken about the character with them, I've always felt that this would be the perfect way to end and complete his journey, and to complete the journey of this series, and they gave it to me.

Human beings, we have dark sides; we have dark issues in our lives. To progress anywhere in life, you have to face your demons.

I remember when I read Walter, for example, six years ago now, I said, "This is the role for me." I said that to my family. There was something there that I knew was absolutely right, and that was just based on the character. That's when gut instinct comes into play. I know there are certain things I won't do.

I'd never done anything that required a five-year commitment. To build a show that seems to have kept the imagination of the world so much was a bit otherworldly.

We've had such a close relationship with the fans. Through social networking and the internet, we have much more contact, and we did go to things like Comic-Con. So, I think people know most of our secrets.

As actors, you don't actually need to know the future of the character. You just need to know the backgrounds.

I don't know where the line is. I don't know how much of myself is in Walter. There's got to be a bit of him there.