CLARA: You can't do this. You cannot pass yourself off as a real person among actual people.

DOCTOR: I lived among otters once for a month. Well, I sulked. River and I, we had this big fight...

CLARA: Human beings are not otters!

DOCTOR: Exactly. It'll be even easier.

(A black rook is knocked over by a football.)

CLARA: Hey, I said you could play chess, I did not say you could play football on the chessboard. Jack, Morgan, come on, help me out, clear it up.

(The Doctor whistles We Don't Need No Education, from Pink Floyd's The Wall.)

CLARA: Okay. Tell me what you're thinking.

DANNY: I know men like him. I've served under them. They push you and make you stronger, till you're doing things you never thought you could. I saw you tonight. You did exactly what he told you. You weren't even scared. And you should have been.

CLARA: I trust him. He's never let me down.

DANNY: Fine. If he ever pushes you too far, I want you to tell me, because I know what that's like. You'll tell me if that happens, yeah?

CLARA: Yeah, it's a deal.

DANNY: No. It's a promise.