Ninth Doctor: "Do you wanna come with me? 'Cause if you do, then I should warn you — you're gonna see all sorts of things. Ghosts from the past. Aliens from the future. The day the Earth died in a ball of flame. It won't be quiet, it won't be safe, and it won't be calm. But I'll tell you what it will be: the trip of a lifetime!"
— Season One trailer
Vincent Van Gogh: "You know, it seems to me there's so much more to the world than the average eye's allowed to see. I believe, if you look hard, there are more wonders in this universe than you could ever have dreamed of."
— Season Five, "Vincent and the Doctor"