It's another showdown between Castiel and Alastair and the former seeks the assistance of Dean in getting an information out of the latter. In the next "Supernatural", Angels are found dead, murdered by someone who uses a stolen Lucifer sword. Castiel and Uriel suspect that Alastair is behind all of this.
The angels have captured Alastair and ask Dean to use the torturing skills he learned in Hell to extract information from him so they can stop the murders. Sam is concerned Dean can't handle the job but Dean agrees to do it. However, when Alastair reveals some shocking information, Dean's world is shattered.
After a long break, the show is back with the episode which is called "On the Head of a Pin", airing March 19.
"Supernatural" has been ordered for a fifth season. Castiel's depicter Misha Collins said that his character will be back for another season. "Well, I've been told that I'm coming back, so the odds are good. I'd have to screw something up between now and the end of the month!" he informed TV Guide.