DOCTOR: When I meet a regime that needs to import savage alien life forms as security guards, I begin to wonder who the real criminals are.

JO: Those creatures aren't really savage.

CONTROLLER: Exactly. They are simply guard dogs. They just do what I tell them.

DOCTOR: You mean there aren't enough humans around that will follow your orders so blindly?

CONTROLLER: That is not what I was saying.

DOCTOR: Isn't it? Then what you're saying is that the entire human population of this planet, apart from a few remarkable exceptions like yourself, are really only fit to lead the life of a dog.