["No," Rei wants to say, "the secret is why." But Rei can't quite bring herself to say it -- Castiel becomes God -- because that makes it final. A possible future, that's what Castiel kept insisting, but Rei was faced with yet another vision that had come true. Possible futures bleeding into certain futures -- it made her physically ill.]

I saw a vision of it, of him -- and he's not himself. He lost everything that he ever was. He turns into a monster. They tore out his Grace so he wouldn't be a threat to anyone, even though he didn't -- he didn't even know what I was talking about, and it isn't as if the idiot can lie. He wanted to change things so badly that he just --

[Rei releases a breath she didn't know she was holding.]

... he can't go home.