Dr who quotes cybermen The Wheel in Space

The Doctor: I suppose you've come for me?
Cyberman 1: You know our ways.
The Doctor: Yes, I hoped you realised somebody did. I imagine you have orders to destroy me?
Cyberman 1: Yes.
The Doctor: Tell me one thing, why did you order Duggan to destroy radio communication with the Earth? After all, that is why you want posession of the wheel, isn't it?
Cyberman 1: You know our ways.
The Doctor: That doesn't answer my question.
Cyberman 2: He was instructed to destroy only the transmitting complex.
The Doctor: Oh, I see, how interesting, yes, of course. And presumably your large space-ship holds your invasion fleet, and the smaller ships can only enter the planet's atmosphere by homing on a radio beam.
Cyberman 1: You know our ways. You must be destroyed.
The Doctor: Yes, I was afraid you'd get back to that.