Wow this story was just... Wow. I love how in character everyone was. It was also great that Cas took the time to actually 'visit' the places he was at in his search for god, I also love how despite the fact that god said 'back off' Cas still wants to look for him when all is done. I like that. Major kudos for Sam picking up the pendant, and also Cas leaving Dean out in the field with his jacket. That was cute. I also love the phone calls from Dean to Cas and how Cas replayed them, it was very beautiful how you worked them in with Cas taking the time to enjoy the scenery.
Awesome story, amazing coda. Loved it!