MASTER: Shut up! Do you want to see my city, Doctor? Do you want to see what happens when you're too late to save your little friend and everybody else?

(He wheels the Doctor to the parapet to watch the columns of people being escorted by patients.)

MASTER: See? This used to be just a hospital. Now it's mass production. The Cyber Foundries.

MISSY: The whole city is a machine to turn people into Cybermen. What do you think? Exciting, isn't it?