This marks the first appearance of Jeffrey Dean Morgan (John Winchester) since the season premiere "In My Time of Dying".

Bobby Singer: Something big is going down. End of the world big.
Dean: Well, then let it end!
Bobby Singer: You don't mean that.
Dean: You don't think so? You don't think I've given enough? You don't think I've paid enough? I'm done with it. All of it. If you know what's good for you, you turn around, you get the hell out of here. Go!

Jake Talley: I'm dreaming, aren't I?
Yellow-Eyed Demon: I got a genius on my hands.

Jake Talley: Go to Hell.
Yellow-Eyed Demon: Been there, done that.

Yellow-Eyed Demon: I’ll make certain that they both live long enough to know the chewy taste of their own intestines.

(to Sam’s corpse)
Dean: When you were little, couldn't have been more than five, you just started asking questions. How come we didn't have a mom. Why did we always have to move around. Where'd Dad go. Take off for days at a time. I remember I begged you to quit asking, Sammy. "You don't want to know." I just wanted you to be a kid. Just for a little while longer. Always tried to protect you. Keep you safe. Dad didn't even have to tell me. It's always my responsibility, you know? It's like I had one job. I had one job, and I screwed it up. I blew it, and for that, I'm sorry. I guess that’s what I do. I let down the people I love. Y’know, I let Dad down, and now I guess I’m just supposed to let you down, too. How can I? How am I supposed to live with that? What am I supposed to do? Sammy? What am I supposed to do? What am I supposed to do?!?

Female Demon: Then no deal.
Dean: Fine.
Female Demon: Fine. Make sure you bury Sam before he starts stinking up the joint.

Dean: What do I have to do?
Female Demon: First of all, stop groveling. Needy guys are such a turn-off.

Dean: Ellen what happened, how’d you get out?
Ellen Harvelle: I wasn’t supposed to; I was supposed to be in there with everybody else. But we ran out of pretzels, of all things. It was just dumb luck.

(about the Roadhouse fire)
Ellen Harvelle: A lot of good people died in there, and I got to live. Lucky me.

Yellow-Eyed Demon: If you're gonna open that crypt for me, you're gonna need a key.
Jake Talley: A gun?
Yellow-Eyed Demon: Oh, this isn't just any gun, Jake. This is the only gun in the whole universe that can shoot me dead.
Jake Talley: Is that so?
Yellow-Eyed Demon: Yep. Here, take it. (Jake aims it at him) Oh my. I'm shocked at this unforeseen turn of events.

Jake Talley: You were dead. I killed you.
Sam: Yeah? Well, next time finish the job.

Bobby Singer: Oh no.
Ellen Harvelle: Bobby, what is it?
Bobby Singer: It's Hell. Take cover, now!

Yellow-Eyed Demon: So, Dean. I gotta thank you. You see, demons can't resurrect people unless a deal is made. I know, red tape, it'll make you nuts. But thanks to you, Sammy's back in rotation. Now, I wasn't counting on that, but I'm glad. I liked him better than Jake anyhow.

(to Dean)
Yellow-Eyed Demon: You of all people should know that what’s dead should stay dead. Anyway, thanks a bunch. I knew I kept you alive for some reason. Until now, anyway. I couldn't have done it without your pathetic, self-loathing, self-destructive desire to sacrifice yourself for your family.

Dean: (killing the Yellow-Eyed Demon) Check that off the to-do list.

Sam: I kinda can't believe it, Dean. I mean our whole lives, everything has been prepping for this and now I... I kinda don't know what to say.
Dean: I do. (he kneels over the demon's body) That was for our mom, you son of a bitch.

Dean: Don’t get mad at me. Don’t you do that. I had to. I had to look out for you. That’s my job!
Sam: And what do you think my job is?
Dean: What?
Sam: You saved my life, over and over. I mean, you sacrifice everything for me, don’t you think I’d do the same thing for you? You’re my big brother. There’s nothing I wouldn’t do for you. I don’t care what it takes, I’m gonna get you out of this. I guess I gotta save your ass for a change.

Ellen Harvelle: Well... Yellow-Eyed Demon might be dead, but a lot more got through that gate.
Dean: How many ya think?
Sam: A hundred. Maybe two hundred. It's an army. It's unleashed an army.
Bobby Singer: Hope to hell you boys are ready. 'Cause the war has just begun.
Dean: Well, then... we got work to do.

When Dean snaps at Bobby, he gets up and the chair falls to the floor with an audible clatter. However, after Dean apologizes, he walks back to the chair which is now standing upright.

When Dean kisses the demon to seal the bargain, his head is tilted to the left. The camera cuts to a new angle and Dean's head instantaneously tilts to the right.

When Sam and Dean stand over the Yellow-Eyed Demon's corpse, Dean puts the Colt in his left jacket pocket with the barrel pointing up. However, later when he takes it out and puts it in the Impala's trunk, the barrel is pointed down.