Title: Storm Front
Author's LJ/DWJ: tielan and seldear 
Categories: Crossover, apocafic
Warnings: None
Author's Webpage/Fic list: AO3,
Why this should be read:

I can't tell you what fandom this crosses over with, because that would spoil it. Trust me, it's fun and well-written (as all of her stuff is). It's medium length and plotty, and well worth several re-reads. Go and enjoy.

Storm Front