In the middle of the last century, the visionary Andrew Ryan appeared and like Captain Nemo from the story of 20,000 leagues under the sea, he gathered around himself the best scientists and with them created a large underwater city called Rapture. The story of the reasons for the formation of the city below the surface of the sea will be revealed to you as you go through the game, but in short Andrew Ryan wanted to separate himself from the rest of the world where scientists will not be hampered in their work. The city functioned well until the discovery of a substance called Adam. Adam was discovered in a species of sea worm and has enabled great scientific results such as influencing genetics. You will discover that something went very wrong as a player after a plane crash in which you, as the only survivor, find salvation right at the entrance to the underwater world of the city of Raptur. You soon realize that what first seemed like salvation is actually the beginning of a new battle to save your own life ….