A middle-aged white man, wracked with fragmented memories and on a quest to find his children, explores an enclosed environment with anachronistic technology and bizarre abominations against nature. As his journey continues, it becomes clear that the protagonist has much blood on his hands and the antagonist - a nihilistic madman with a penchant for hammy speeches and an army of mindless followers - is quite familiar with him. At one point, the society which the protagonist has become quite disgusted by is set upon by the antagonist's hordes.

It turns out that the protagonist and antagonist are one and the same - different incarnations of the same being, one a blank slate hoping to undo the error of their ways and the other driven to despair by atrocities into drowning the world in blood. The protagonist learns that he sacrificed his own children in pursuit of his goals, and ultimately learns that the only way to undo his sins is to join with his dark half and kill himself.

Infinite tried way too hard to differentiate Booker from the villain, to the point that there's actually no resemblance and the hand-waves they do regarding their physical differences only raise further questions - why does he turn into Santa Claus while his daughter remains a pretty young thing? A Machine For Pigs has the decency to make Mandus' two selves more plausibly originated from the same hateful seed by never showing what they look like.

In addition, Bioshock choked on its fascinating concept in favor of a painful cop-out (metaphorically going with the "Kill Hitler to stop WW2" scenario). It negates everything that happened, which is extremely frustrating from a story-telling perspective, while A Machine For Pigs instead leaves us with an uncertain future.

Oswald is an alternate form of Booker DeWitt.