In 2014, Dean Winchester led a raid on the asylum in Detroit where a Sam-wearing-Lucifer was waiting for him. Everyone knows what happened next: the Chitaquan soldiers who accompanied Dean died horribly at the hands of Lucifer’s minions while Lucifer murdered Dean in the garden below and warned the Dean from days past that no matter what he tried, he would always end up there. There were no survivors.
Or were there? This story picks up where “The End” leaves off, from Castiel’s perspective from inside the asylum, a twist of fate, and conditional divine intervention no one saw coming. It details what happens after Lucifer dies, Dean lives, and the world doesn’t actually stop turning. A canon-compliant “fix-it” fic for the Endverse and a Dean and Cas who deserved better.
Or: "The End" was not the End. This is the story of what came after.