>game is set in the mid 80s
>you are sent with an expedition team by a shady biochem company to go down to rapture and acquire some adam slugs for the sake of finding a way to mass produce them on the surface
>your team is sent down with multiple other teams
>but as you descend and get close to the city some giant monster attacks your vessels and you end up crashing into part of the abandoned city
>you’re the only survivor on your team
>you get a signal showing one of the other pods is nearby and make your way to it
>as you get to the sub you find a radio and get a call from the leader of the one of the other teams
>they tell you to rendezvous with them at their crash site and bring the battery for your sub as theirs is broken
>they also tell you to continue collecting slugs for the mission
>rapture at this point has become more of a mess and the remnants of its people are horrifically mutated abomination
>some remain slightly human while others have melded with the sea life like the thing that took out your and the other teams as well as some of the plants and insects in arcadia.
>plasmids and weapons come from a mix of leftovers in rapture and experimental ones brought for the expedition.
>you also collect slugs for both adam and the fulfill the mission you were sent on
>along the way you find out that another expedition was sent about a decade prior and met a similar fate as yours