M&S fighting zombies with Dean and Sam
I'm looking for a fic where Mulder and Scully are holed up in an abandoned cafe with Supernatural's Dean and Sam Winchester fighting off zombies. I think there is a first half or first part to this that takes place years before where Mulder recognized John and the boys, then teenagers, in a cafe and tried to talk to them even as they paid there tab and left, following them out, then getting punched in the face by Dean.