The Doctor: Don’t challenge me, Harriet Jones. ‘Cause I’m a completely new man. I could bring down your Government with a single word.

Harriet Jones: You’re the most remarkable man I’ve ever met. But I don’t think you’re quite capable of that.

The Doctor: No, you’re right. Not a single word. [pause] Just six.

Harriet Jones: I don’t think so.

The Doctor: Six words.

Harriet Jones: Stop it!

The Doctor: Six. [approaches Alex, whispers in his ear] Don’t you think she looks tired?

Doctor Who, “The Christmas Invasion”