I finally managed to beat the game on my non lethal walkthrough and got clean hands. However I failed to get Ghost in the flooded district.

Question is: Do I have to redo flooded district only, if that was the only mission I failed to get ghost, or do I have to redo everything FROM the flooded district to the end of the game?

The achievement/trophy unlocks at the end of the last level so my guess is you have to redo everything from the Flooded District to the end of the Lighthouse.

Thanks Alvin. Time to get started then

Most frustrating thing with ghost is never knowing where you went wrong.

If you want you can watch my stealth videos for the Flooded District (youtube.com/redrobin183) I managed to complete the mission w/o kills, KOs or alerts.

(Apologies if advertising YouTube videos is prohibited here)