DOCTOR: Yes, Leela. I’ve been trying to educate you.

LEELA: I have learnt more than you know.

DOCTOR: Really? How to kill more efficiently? How to show no mercy? Who are you learning from, Leela?

Me or the evil out there in the universe?

LEELA: I have learnt that evil must be fought. That sometimes the hard way must be taken.

DOCTOR: Don’t ever presume to tell me about evil and the hard way, Leela. I’ve spent the best part of my

lives facing difficult choices and trying to do the best I can. I didn’t teach you to be ruthless, to snuff out lives

without a second thought. Is that what you think I’ve been trying to teach you all this time, hmm? Because if

it is, either you haven’t been listening or… or I’m a bad teacher.

LEELA: Doctor, your way is good, but it does not always work.

DOCTOR: If there’s a chance to save lives, we must always take that chance.

LEELA: But I was right, Doctor. I know I was.

DOCTOR: Beware of that kind of certainty, Leela. It can lead to the worst excesses of evil.