BioShock Infinite

=== Setting and characters ===

BioShock Infinite is set in 1912 and takes place in a floating steampunk city-state in the sky called "Columbia", named for the female personification of the United States. The city of Columbia was founded by self-proclaimed prophet Zachary Hale Comstock, and funded by the United States government as a floating world's fair and display of American exceptionalism in the 1890s. Tensions rose between Columbia and the government after the city independently intervened in the Boxer Rebellion, and Columbia ultimately seceded from the United States and disappeared into the clouds. Comstock transforms the city into a theocratic police state, with Comstock worshipped as a prophet, and the Founding Fathers of the United States venerated as religious icons. Institutional racism and elitism are widespread in the city, with minorities serving as a labor underclass of Columbia. By the events of the game, Columbia is on the verge of civil war; the Founders of Columbia are opposed by the Vox Populi, a resistance group led by Daisy Fitzroy who fight for the rights of the marginalized.
Columbia is home to "Tears" in the fabric of space-time. These Tears reveal alternate universes. Some individuals exploit the insight offered by the tears to create new weapons and technologies, while several others replicate futuristic media heard from the Tears, bringing anachronistic elements into Columbia.
The player controls protagonist Booker DeWitt, a U.S. Army veteran and disgraced member of the Pinkerton National Detective Agency scarred from a life of violence. Faced with mounting gambling debts, he is sent to Columbia to find a young woman, Elizabeth, who has the ability to open Tears. Confined in isolation in Columbia since childhood, Elizabeth has been groomed as the city's future leader and is guarded by Songbird, a large, robotic bird-like creature who has served as both her friend and warden. Two individuals, Robert and Rosalind Lutece, direct Booker to Columbia and appear throughout his travels. Though they appear as twins, they are revealed to be the same person from two different realities, having figured out how to communicate through and subsequently cross realities.

Plot

In July 1912, Booker DeWitt arrives in Columbia, where he is soon pursued by authorities who recognize him as a "False Shepherd" who is prophesied to attempt to corrupt Elizabeth and overthrow Columbia. Freeing Elizabeth from her tower, Booker narrowly evades Songbird. Commandeering an airship, Booker lies that he will take Elizabeth to Paris; when she realizes they are going to New York City to fulfill Booker's debts, Elizabeth knocks him unconscious and flees. Booker awakens to find the airship commandeered by Daisy Fitzroy, who offers to return the ship if Booker helps her arm the Vox Populi.
Booker and Elizabeth reunite and join forces to secure weapons from a local gunsmith. Traveling through Tears, they arrive in a world where Booker is a Vox Populi martyr and open warfare has erupted in Columbia. Elizabeth kills Fitzroy to prevent her from killing a Founder boy. Booker and Elizabeth regain control of the airship; however, Songbird attacks as they attempt to flee, and they crash back into the city. Elizabeth and Booker discover a conspiracy behind the city's founding: Comstock, who had been rendered aged and infertile as a result of his frequent exposure to Tears, obtained Elizabeth from another reality and then killed his wife and the Luteces to hide the truth of the child's origin, framing their deaths as assassinations. Comstock then isolated Elizabeth in Columbia, constructing a large Siphon to control her power.
Elizabeth is recaptured by Songbird and is tortured and brainwashed back into obedience to Comstock. Pursuing her, Booker is brought forward in time to 1983 by an elderly Elizabeth as Columbia attacks New York City. The elderly Elizabeth returns Booker to 1912 with information on how to control Songbird, in hopes he can save her younger self. Booker rescues Elizabeth, and the pair pursue Comstock to his airship. Upon meeting Comstock, he demands that Booker explain Elizabeth's past to her; enraged, Booker drowns Comstock in a baptismal font. Booker denies knowledge of Elizabeth's past, but she asserts that he has merely forgotten. Booker and Elizabeth direct Songbird to destroy the Siphon, unleashing Elizabeth's full powers.
Elizabeth opens a Tear and transports them to the underwater city of Rapture. The newly omniscient Elizabeth explains there are countless alternate worlds and versions of Booker and Elizabeth; their reality is one of an infinite number depending on their choices. Elizabeth reveals that Robert Lutece approached Booker on behalf of Comstock to acquire Booker's infant daughter, Anna DeWitt, in exchange for erasing his debts. Booker later attempted to renege on the deal and take Anna back; however, Comstock narrowly escaped through a Tear, which severed a tip of Anna's finger as it closed. Comstock then raised Anna as his own daughter, Elizabeth; her severed finger, which caused her to exist in two realities simultaneously, is the source of her ability to create Tears. Robert Lutece, angry at Comstock's actions, convinced Rosalind to help him bring Booker to the reality where Columbia exists to rescue Elizabeth.
Elizabeth explains that despite Comstock's death in their reality, he will always remain alive in alternate universes, since the Luteces have enlisted the Bookers of numerous different universes to try to end the cycle. Since stopping Comstock requires preventing his birth, Elizabeth takes Booker back in time to a baptism he attended while in the Army, following his participation in the Wounded Knee Massacre. She explains that, while Booker rejected the baptism, in the universes in which he accepted, he was reborn as Zachary Comstock. Booker, joined by other universes' Elizabeths, allows them to drown him in the river, preventing Comstock's existence. One by one, the Elizabeths begin to disappear, with the screen cutting to black on the last.
In a post-credits scene, a Booker awakens in his apartment on October 8, 1893. He calls out for Anna and opens the door to her room before the screen cuts to black.