Your character's introduction to the world of BioShock is going to be a pretty tried-and-true way of getting you into an unusual environment where you need to explore and learn in order to survive. When your plane crashes in the middle of the ocean, your only hope is to swim to a nearby tower jutting out from the water. Once there, you are taken into a rickety old elevator that takes you tens of fathoms underwater. During this ride, you are also introduced, via a short video, to what this unusual place is.
Rapture is an underwater city that looks like Gotham City, just submerged, built decades ago by a man who wanted to allow science to grow without the restrictions of ethics and government interference. But it seems something has gone horribly wrong because there seem to be parts of Rapture that are flooded and strange creatures running around. Now, in order to survive, you need to find out what has happened to this underwater science utopia, and figure out a way to get back to the surface and get rescued.