TEGAN: I'm not coming with you.
DOCTOR: I beg your pardon?
TEGAN: I'm tired of it.
DOCTOR: What's the matter?
TEGAN: A lot of good people have died today. I think I'm sick of it.
DOCTOR: You think I wanted it this way?
TEGAN: No. It's just that I don't think I can go on.
DOCTOR: You want to stay on Earth.
TEGAN: My Aunt Vanessa said, when I became an air stewardess, if you stop enjoying it, give it up.
DOCTOR: Tegan
TEGAN: It's stopped being fun, Doctor. Goodbye. Turlough.