"Well, yeah, but that's just Cas." In that it was pretty normal for him to look like a confused puppy.

It's the yet that bothers him, but Sam doesn't say anything. Because he's pretty sure it's going to bother Gabriel, too. "Well, there's all sorts of books at the bunker you could sink your teeth into, if you liked. Nothing that needs immediate translating, of course, but there's a lot of old texts there that could be up your alley."