Booker DeWitt is the protagonist of BioShock Infinite, whom the player controls throughout the game. He is a private investigator and, prior to his reluctant arrival in Columbia, a former soldier and Pinkerton agent. Booker is offered a deal to wipe away his gambling debts if he goes to Columbia and retrieves a girl imprisoned there. Over the course of the story, Booker reveals his past experiences, and shows his ability to make decisions independent of the player.
Zachary Hale Comstock is the leader of the Founders, the ultra-nationalist/nativist party that founded the floating city of Columbia, and the main antagonist of BioShock Infinite. Within Columbia, Comstock has earned the titles of "Prophet" and "Father Comstock." He claims to have the ability to predict the future of Columbia, attacks from his enemies, and the actions of The False Shepherd.