just because they throw in a little backround lore that you find out in audio logs, cut scenes, and loading screen quotes from Isabel. (or whatever her name is) doesn't mean there is a story behind it. besides what they tell you in these audio logs is really the whole story. the world was flooded, there was a race to get to the ark. only a few american's got there (mostly jamacians and europeans judging from voices) now the world is *drying out*