As soon as Castiel was on his way, Sam called Dean. There were all sorts of alarm bells ringing in his mind as he gave his brother the lowdown on what he suspected was happening with Castiel.

Not that they have proof that the relationship is abusive, but untreated abrasions and the way that Castiel has been withdrawing definitely point that direction. It's different abuse that Sam and Dean were used to growing up, but there's still enough that they can make a guess.

So they decide to stake out near Jason's home. They know where it is, have always known, but out of respect for Castiel, they haven't gone near it. Now, though? Now the rules are changing and there's always one of them there, since the house across the road fortuitously went up for sale. And even if Sam's faith has been tested a million times, part of him breathes a prayer of thanks to a God who stepped away and hopes that they'll find out what they need to.