this fic is set directly after the fall and basically cas can't (or doesn't want to) find dean and sam so instead goes off and works with these two sisters for a long time. one of the sisters is around sam's age and the other one is a lot younger (12ish i think). at one point the sisters spilt up when they're working on a case (young one stays with cas, older one goes off by herself) and the older one runs into sam and dean and starts working with them and eventually they all meet up and work together. also i think throughout the story cas is being chased by angels but i could be wrong