Today I was suddenly reminded of a fic that I read a while ago that I am now having trouble finding, which either means that I didn't tag it well enough, or I forgot to save it.
Details: Dean's has been sent to hell and Sam doing everything he can to try to get him out. Sam eventually goes to Gabriel (who is still disguised as a Trickster) to ask him for help; Gabriel agrees to help out Sam. So the 2 of them come up with a plan that will somehow get Sam into hell to pull Dean out. (I don't remember what the exact plan was.) However, once the plan is put into action, Sam learns that it was for nothing; Dean has already been rescued.
Some time passes and the brothers talk about Dean's hell-break. Sam goes on to tell Dean that he had came up with a plan to save Dean but that the plan had ended in failure. Dean responds by saying that everything alright because Dean was rescued anyway. However this only leads to Sam saying that he feels that he failed as Dean's brother because the two of them always rescue each other and this time Sam didn't do that (thus break the status quo).
Found: It's
The Promise at the End of This Book by
electrolitestar.