TENTH DOCTOR: A good friend of mine once said I needed people to stop me. But I get things done on my own.

FOURTH DOCTOR: I shouldn’t need stopping! Other people should be what keep us going!

TENTH DOCTOR: Maybe I thought that once, back when I was you. What keeps me going now are the likes of them - Daleks. The worst things in the universe. There are so many out there, you’ve only scratched the surface. If ever I ask myself “have I the right to do what’s needed to beat them?” You know what I think now?

FOURTH DOCTOR: What?

TENTH DOCTOR: Yes, I do.