In this episode, Sam and Kevin need Crowley to help the decipher some of the ancient writing on the Angel tablet. Of course, Crowley is only willing to help for something in return. Crowley requests to make a call to Abanddon (the demon who has taken over running hell). In order to make a call to another demon, a bowl of blood must be present. Kevin fills a couple syringes of blood leaving a few left over. Near the end of the episode when Sam is putting everything away, he notices a syringe missing.
Sam heads back to the dungeon where Crowley is being held but stops before Crowley notices him. Sam stands near the doorway and watches as Crowley injects himself with the missing syringe. Of course the episode ends there, leaving it open for interpretation. To me this could either the beginning of a very interesting character development, or a get ‘out of jail free card’. Does Crowley really want to become human? Or does he want to become human enough to escape the devil trap? I think it would be very interesting watching Crowley’s transformation back to a human being. Would his personality drastically change? Would he still be as confident and brute? Or would he return to the human who sold his soul to a demon for a couple extra inches down there…