Everything had happened so fast. Charlie and Dorothy had defeated the Wizard, then she came back to Earth, only to have been split into a 'good' and 'evil' side. Thankfully, they had made Charlie whole again, but not before Dean had put a hefty beating on the evil side, which unfortunately caused Charlie to have all of the injuries after. Dean wasn't entirely at fault, though. She knew that he had been plagued with the Mark of Cain, which had caused him to be more violent. She had forgiven him before she went off in search of a book to help cure him, but she could tell that Dean hadn't forgiven himself for what happened. Well, that and for whatever had happened that ended up killing Charlie before Dean was rid of the Mark. She wasn't quite sure what it had happened to her because Sam and Dean didn't want her to know. So of course, they shut down Castiel after he had let it slip that she had died shortly after she had come to Knowhere in their timeline.
A lot had happened since Charlie had found herself on the giant space head. First a major battle, in which she had suffered a minor injury. She had fully healed since then, but only to be completely traumatized by being turned into some adorable yarn doll. She still hadn't quite recovered from that, but she had gone back to work and was able to put on a smile without anyone knowing the difference. She didn't hide it while she was in the barracks, though. With Cas below her and Mary across from her, she had fully admitted how she felt about what had happened to her.
Charlie decided to go for a walk for her lunch break that day. She wanted some fresh air, or well rather, as fresh as they could get in space. As she walked around the market, she saw a large dog next to what appeared to be a man in a trench coat. Castiel. She smiled as she walked over to her friend, after making her way around a couple of arguing merchants. She sat down next to him, not saying a word. Just staring off in the direction that he was.