Castiel makes it clear that he is no longer an ally to Sam and Dean in a newly released clip for the first episode of "Supernatural" season 7. The Winchester brothers are about to kneel in front of Cas as it is suggested by Bobby before Cas stops them because he knows they don't mean it.
"Cas, c'mon this is not you," Dean says, but Cas replies, "The Castiel you knew is gone." In the end of their failed attempt to pledge allegiance to Cas, they receive a threat from their former ally who says, "I hope, for your sake, this is the last you see me."
In the premiere episode titled "Meet the New Boss" which will air Friday, September 23 at 9 P.M. on The CW, Dean decides they should bind Death and order him to stop Castiel, but the former angel is one step ahead of them. Meanwhile, Sam struggles to deal with the broken wall in his head.