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

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.

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

My last two characters have been Denethor and Walter Bishop. Both will be hard acts to follow. That sits in the hands of my managers, at present. I just have no idea what's going to be offered 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 suppose, when you start up in acting, you hope to be given challenges, and you always have dreams about the things you could do and couldn't do, but normally we get pigeon-holed a little bit, as we go on in our careers.

Many very strong fathers have turned out ineffectual sons by not allowing them to grow as men.