is this a fusion or a crossover?
summary: Charlie Eppes in a post-apocalyptic world...then it gets strange.
Charlie Eppes braced himself against the wind and all it held, physically and in memory. His broad-soled boots began to sink from being still too long, thus he mushed himself forward again.
There was no time for self-recriminations - none of his programs had forseen this outcome - but then, there never was, really. No time for anything save forward motion.
There were others, Charlie knew, eking out the remainder of existance within the sand-swamped City.
The light was flicked on, door opened. "I don't believe it. I refuse to believe it," Richard Castle said. "My daughter, my flesh-and-blood, my heir, is writing fanfiction!?"