Quote of the Day (5/16/11) (The Tenth Doctor Week Two)

[After travelling to 1599]
Martha: But are we safe? Can we move around and stuff?
The Doctor: Of course we can. Why do you ask?
Martha: It's like in the films! You step on a butterfly, you change the future of the human race!
The Doctor: [Bemused] I'll tell you what then, don't... step on any butterflies. What have butterflies ever done to you?
Martha: What if... I dunno! What if I kill my grandfather?!
The Doctor: Are you planning to?
Martha: No.
The Doctor: Well, then.
--“The Shakespeare Code”