"No." Castiel doesn't elaborate because Castiel just doesn't elaborate.

He knows Dean wants to talk and Castiel doesn't feel like walking when the Leviathan could easily catch up to him after pulling its head back onto its shoulders, so he flicks the safety onto his shotgun, retrieves the knife from the door as he passes and heads out to the side of the Impala.

...actually, he isn't sure if he's allowed in the front seat or if he has to sit in the back. It seemed like the front seat was usually reserved for people Dean liked, so Cas shifted on his feet awkwardly, feeling too different in his jeans and shirt and army surplus jacket, gun cradled in his arm, knife strapped around his leg.

Flying blind. That was the phrase.