You're always working with the relationships. It's pretty demanding, but then again I love that.

[on playing Walter] It was wonderful to be able to play a character who had so many colors and who was able to play comedy, to play incredibly vulnerable, which he did a lot of the time, to play the love story, and to play the relationship with the son, which is quite unusual. That's a gift to me, as an actor. It was like everything you could possibly hope for, over five years. So, I was a very lucky actor.

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.

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.

I find science really sexy and, at the time that I was a school kid, it certainly wasn't.

We didn't know until really quite late in the piece how Joel [Wyman] would finish it off.

I think the glue that held Fringe together was the relationships.