Atlantic Waters 1968
Off the coast of Iceland, the I.S. Concourse was a ship launched by the outer world to retrieve resources from the no longer dependable city-state of Rapture to help provide for poor countries who have fallen low to Soviet Experiments across Europe. On September 14, a company of high-classed pirates boarded the Concourse to Rapture after recieving a world-wide released telegraph describing feed back from a survivor who documented his experiences within Rapture. A man named Augustus Sinclair.
As they submerged into the depths of Rapture, only half of the crew made it along the borders of the now ancient city; the rest of them killed by upcoming debris caused by the liberation of a friend of Augustus Sinclair, Johnny Topside.
The wreaked havoc that occurs frees a man with more knowledge than anyone. Oswald CiCiero. The right-hand man of Andrew Ryan who was betrayed by Atlas because of his keen philosophy that opposed the cause of Rapture, and thus the bonds that held the city together outbroke into a civil war.
The remainder of the I.S. Concourse are attacked by a scourge of Splicers led by a new breed of The Family, ADAM recyclers freed of their armor and engulfed by individuality, the Fathomes.
Oswald, now conscious, observes his and Ryan's creation, the light of the horror. In his pocket, Rapture's Genetic Key, and a radio attached with a log left by Andrew Ryan, who reveals that the cure to the side effects of ADAM is in his blood.
Oswald can no longer control the city with a mere 'key' and is once again imprisoned, this time, by the Fathomes who value him deeply because of his immunity and depressant to ADAM. Oswald breaks free, and manages to ressurct Andrew Ryan via a found plasmid. The crew of the Concourse manage to escape as well by the overuse ADAM, turning them into Splicers, whom a new Andrew persuades under his idealogy. Oswald is choiced to destroy, or escape his latest project, freedom.
Oswald escapes the Fathomes, but is hunted down by a pack of Splicers equipped with Big Daddy Armor. He loses them in Fort Frolic, and has a chance to gather up ammunition, gather ADAM via Little Sisters, and follow an escape route to higher land given to him through audio tracks left behind by Andrew Ryan, who wishes for Oswald to rule the city with him.
Oswald battles through the Fathomes' army of Rapture from Fontaine Futuristics to a flooded Peresephone to Dionysus Park, where he is confronted by Andrew Ryan.