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While talking to Misha Collins about his charitable scavenger hunt (more about that here), he also confirmed a hunch we’d had about the last time Dean saw Cas. It was, in fact, while Dean was exiting Purgatory. But there’s much more to it than that. “That very moment is a pivotal moment. I think Dean is confused about what happened at that moment and won’t actually find out what happened then until episode 7,” he reveals. “It’s going to take a while to see that moment play out.” Suffice to say the truth hurts — especially on this show.
But when Cas does return topside, look for him to be “reinvigorated with a sense of purpose,” says Collins. “He essentially feels like he has to do good in order to right the wrongs of his past. So he starts to collaborate with Sam and Dean for that reason — so that he can continue to try to make things right. He’s no longer paying penance, really, because it’s no longer an act of suffering for him. But he’s doing his best to right the wrongs of his past.” Doing so won’t be as easy as he hopes, however. “He’s doing that in ways that help Sam and Dean and then, ultimately, it might also make life — as per usual with the Supernatural universe — complicated for Sam and Dean. At first, it seems like everything is hunky dory. But things quickly fall apart.”