Sofia Lamb

Doctor Sofia Lamb, has taken over Andrew Ryan's position as the leader of Rapture, albeit with completely different view.

Lamb was an old political rival of Ryan, and is in many ways his opposite.

She is an Altruist, and beliefs we all have a duty to the world, and she has allowed those beliefs to corrupt her. And in the name of the greater good, she's begun to see people as numbers. To make the world one family.

And that is why she comes into contact with the player, a lone agent, an extremely powerful individual, fighting with her collective.

She is a part of Rapture's history, and through reasons discovered in BioShock 2, you find out why she wasn't present during the events of BioShock.

During the game, information about her will be revealed through dialog of Andrew Ryan (supposedly through Audio Diaries and, perhaps, ghost scenes).