So. Bobby Singer could no longer walk. Dean was losing faith in . . . pretty much everything. Sam was reconvinced he could hide from hunting and the supernatural world -- this time, because he felt he was a danger to it, rather than the other way around. Raphael, who apparently thought he'd blown Castiel up or some such foolish thing like that, believed God to be not just AWOL, but totally apathetic to humanity's plight in the Apocalypse -- and oh yeah, was a total jerk.
And Dean wasn't entirely clear on why Castiel was so blase about the brothel and insistent that it wouldn't work, this wasn't where he "got laid".
But then, judging by the way he tended to stare at Castiel, Dean wasn't entirely clear on a lot of things about him, these days. It didn't help that Castiel tended to say things like "You shouldn't have let Sam go. You don't have an Alec to look after you in this world." Or that he asked once if Vkandis would be willing to lend a hand.
Really, Castiel was no longer certain why he'd been to Fandom at all, now. It wasn't as though his experiences there were helping very much.
When Dean told him to hold off on fetching him from his hotel until the next morning, Castiel's first instinct was to stand by the side of the road all night. Then he thought about what Chuck would have to say to him doing such a thing, and decided to find something else to do instead. He considered Vegas -- that seemed a more Fandom!Dean or Chuck place to spend a night, but decided that he would only be confused without either of them there to explain things to him. Instead, he went somewhere he believed would make sense.
Which was how, while Dean was transported into the not-so-distant future by Zachariah to hang out with a stoned!mortal!Cass and learn how screwed up the world would be if he continued to hang out saying "no" without his brother, Castiel ended up in the Vatican, telling off the Pope.
[ooc: NFB due to distance. One might assume that the events of Supernatural season 5 episodes 2-4 otherwise went pretty much as they did in canon.]