(Dean finds a dog...)

Dean Winchester: Don't worry about him. He'll warm up to you. Maybe we'll let you sleep in his room. Here we go. Good boy. Hey. Come here. You know, believe it or not, you're the best thing that's happened in the last few days. Yeah, you are. Good boy.

(The dog disappears, Chuck shows up smiling at Dean...)

Dean Winchester: Unbelievable. (Later to Sam): Can't even save a friggin' dog.

Sam Winchester: Yeah, maybe that's the point. No one left to help. No one but us.