Dean Winchester : The Darkness is out there. And the world is gonna burn and once she gets started, that's the end. Of everything, including you. Sam's the only one who can stop it.
Billie : How's that?
[as Dean isn't able to answer]
Billie : I thought so. It's cute, though. You're pretending you're trying to save Sam for the greater good when we both know you're doing it for yourself.