I loved this! There's so little Sam/Cas out there and it's always a pleasure when a story pops up. I liked this slow, winding build up to maybe more. I believe Cas when he says he let Dean go--this doesn't seem like a Cas who could lie. :) Still, I bet it hurt a little to have to be so central to losing a part of your past. I'm sure Sam will help to make it all better.