The single-player campaign is set 10 years after the events of BioShock, when, "along the Atlantic coastline, a monster has been snatching little girls and bringing them back to the undersea city of Rapture."
The multiplayer component is set before the first game, allowing gamers a glimpse of life in Rapture as things started to go wrong in the undersea utopia, providing "a rich prequel experience that expands the origins of the BioShock fiction."