About a year ago, IIRC, somebody came up with an extremely well written fanfic-type story written in terminal style, which was hosted in the Story page and received considerable attention. It started with a damaged human military vessel which is damaged in battle and evacuates its dropships to a nearby planet, which is found to be riddled with Forerunner or Jjaro tunnels. The ships AI is used to infiltrate these, and the protagonist (first person: you) is shuttled about at its whim to counteract the Covenant and Flood hostiles around.
I really want to re-read this story, but can't seem to find it. Does anybody know what I'm talking about, and have a link?