Castiel tries not to look as stunned as he feels, because of all the things he'd expected Dean to shout at the Leviathan, that was not what he'd expected. Not even close. Castiel would take a moment to wonder about the meaning except that a beheading really does just slow them down, and they should get while the getting's good.

"Dean." Castiel starts for the door. "Do you have a vehicle?"