BLACK DALEK: The Doctor will open the Ark!

DOCTOR: The Doctor will not.

BLACK DALEK: You have no way of resisting.

DOCTOR: Well, you got me there. Although there is always this.

BLACK DALEK: A sonic probe?

DOCTOR: That's screwdriver.

BLACK DALEK: It is harmless.

DOCTOR: Oh, yes. Harmless is just the word. That's why I like it. Doesn't kill, doesn't wound, doesn't maim. But I'll tell you what it does do. It is very good at opening doors.