DOCTOR: See? Compressed information. Tons of it. That is the history of London, 1066 to the present day. This is like a disc, a Cyberdisc. But why would the Cybermen need something so simple? They've got to be wireless. Unless, they're in the wrong century. They haven't got much power. They need plain old basic infostamps to update themselves. Are you all right?

NEXT DOCTOR: I'm fine.

DOCTOR: No, what is it? What's wrong?

NEXT DOCTOR: I've seen one of these before. I was holding this device the night I lost my mind. The night I regenerated. The Cybermen, they made me change. My mind, my face, my whole self. And you were there. Who are you?

DOCTOR: A friend. I swear.

NEXT DOCTOR: Then I beg you, John. Help me.

DOCTOR: Ah. Two words I never refuse. But it's not a conversation for a dead man's house. It'll make more sense if we go back to the TARDIS. Your TARDIS. Hold on. I just need to do a little final check. Won't take a tick. There's one more thing I cannot figure. If this room's got infostamps, then maybe, just maybe, it's got something that needs infostamping.