Episode 8 Cold War

Clara: Are we going to be okay?
The Doctor: Oh, yes.
Clara: Is that a lie?
The Doctor: Possibly.

The Doctor: A native of the planet Mars. And we go way back. Way back.
Zhukov: Martian, you can't be serious?
The Doctor: I'm always serious. With days off.

The Doctor: Skaldak won't talk to you. You're--you're an enemy soldier.
Zhukov: And how would he know that?
The Doctor: A soldier knows another soldier. He'll smell it on you, smell it a mile off.
Zhukov: And he wouldn't smell it on you, Doctor?

Clara: How'd I do? Was I okay?
The Doctor: This wasn't a test, Clara.
Clara: I know. But...
The Doctor: You were great, yeah.
Clara: Really?
The Doctor: Really.

The Doctor: Professor, I could kiss you.
Grisenko: If you insist.
The Doctor: Later.

Skaldak: My world is dead! But now there will be a second Red Planet. Red with the blood of humanity.