Dean and Sam in “Unfinished Business”

Dean

What, are you going for, like, the Guinness record of caffeine consumption? That's like your fifth this morning.

Sam

Yeah, well, every time I close my eyes, Lucifer is yelling into my head. It's like I let him in once, now I can't get rid of him.

Dean

You know he's not actually...

Sam

Yeah. Yeah, no. I know. Uh, try telling that to the volume control inside my brain.