MASTER: We go back a long, long way, the Doctor and I. We were at school together, we went out into the universe together. We’ve even killed each other a few times and that always gives you a very special bond with someone.

MASTER: In the wrong hands it could prove a very powerful tool. And I, Doctor Chenka, am very much the wrong hands.

LIV: And there was I thinking you were very much a powerful tool.