From a Safe Distance by bigboobedcanuck
I can't believe this hasn't been retreaded... has it? Was it just tagged wrong?
This is, I believe, the first HIV scare fic I ever read in fandom. I hate it when that theme gets exploited for cheap angst, but when I tell you this is by the great classic QAF fan fic goddess bigboobedcanuck, so there's nothing cheap about it.
It's post-414 but is consistent with canon up until that point.