"Bioshock Infinite" is a first-person shooter video game developed by Irrational Games and published by 2K Games. Released in 2013, it is the third installment in the "Bioshock" series. The game is set in the flying city of Columbia in an alternate history early 20th century, and it follows the story of Booker DeWitt, a former Pinkerton agent, as he embarks on a mission to rescue a mysterious woman named Elizabeth.

**Plot Summary:**

**Prologue - Baptism of Fire:**
The game begins with Booker DeWitt being offered a chance at redemption for past sins by retrieving a girl named Elizabeth from the city of Columbia. As Booker arrives in Columbia, he discovers it is a floating city in the sky, built on a foundation of extreme American exceptionalism and religious fervor. The city's founder, Zachary Comstock, is worshipped as a prophet.

**Act 1 - Rescuing Elizabeth:**
Booker locates Elizabeth, a young woman with unique abilities, and promises to take her to New York. However, Elizabeth is kept captive by the mysterious Songbird, a mechanical creature created by Comstock to protect her. As Booker and Elizabeth attempt to escape, they face the zealotry of the city's inhabitants and the enigmatic Luteces, who appear to manipulate reality.

**Act 2 - The Vox Populi:**
The story takes a dark turn as Booker and Elizabeth become entangled in the conflicts between the Founders, who rule Columbia, and the Vox Populi, a rebel group fighting for equal rights. The narrative explores themes of racism, class struggle, and the consequences of unchecked power. Booker and Elizabeth must navigate a city on the brink of revolution while uncovering the mysteries of Elizabeth's powers.

**Act 3 - Comstock House:**
Booker and Elizabeth discover more about the origins of Columbia and the dark secrets surrounding Comstock's rule. The narrative delves into alternate realities, revealing connections between characters and exploring the consequences of choices made in different timelines. The enigmatic Luteces play a crucial role in guiding Booker and Elizabeth through these realities.

**Act 4 - The Hand of the Prophet:**
As the narrative builds towards its climax, Booker and Elizabeth board Comstock's flagship, the Hand of the Prophet. The story confronts themes of destiny, identity, and the impact of choices. Elizabeth's powers, linked to tears in the fabric of reality, become central to the plot as Booker faces revelations about his own past and the true nature of Columbia.

**Act 5 - The Sea of Doors:**
The game's conclusion takes Booker and Elizabeth to the mysterious Sea of Doors, a place between realities. The narrative explores complex ideas of quantum mechanics and the consequences of infinite possibilities. The story reaches its resolution with a series of shocking twists that reshape the player's understanding of the characters and the world of "Bioshock Infinite."

**Themes:**
"Bioshock Infinite" explores themes of American exceptionalism, racism, nationalism, and the consequences of unchecked power. The narrative is known for its intricate storytelling, complex characters, and mind-bending exploration of alternate realities. The game received critical acclaim for its narrative depth, thematic exploration, and immersive world-building.