Castiel calls Sam to find out where the boys are - the Enochian Sigils he etched into their ribs, hides them from all angels including Castiel. He is angry, that he has killed his brethren and is cut off from Heaven. He tells Bobby this means he can't heal him. He then says in order to defeat Lucifer he plans to find God. He asks Dean for his amulet which he says will burn hot in God's presence.