Comstock, who needed a blood heir for Columbia, having been rendered sterile by the twins' reality-warping experiments. Booker later had a change of heart and chased down the Luteces as they stepped through a Tear, severing the tip of Elizabeth's finger which gave her the awareness of multiple realities. Elizabeth asserts that there has been an endless cycle of Bookers and Comstocks, and the only way to end this is to destroy the creation of Comstock; she takes Booker to the site of the baptism and drown Booker with the aid of dozens of other Elizabeths from other timelines. The Elizabeths begin to wink out of existence, with the game fading to black on the one throughout the game. Burial at Sea In Burial at Sea, Elizabeth approaches Booker – in this reality, a private detective in Rapture – to help them find a missing girl named Sally. They trace her whereabouts to a derelict department store, during which Booker suffers flashbacks to his baptism, but unable to explain them. When they finally find Sally, they find she has been changed into a Little Sister, and Booker suffers more flashbacks, recalling his daughter Anna, before becoming aware of his true nature: he had been one of the Bookers that became a Comstock, but in his attempt to get Anna from another Booker, she was killed. In his remorse, this Comstock reverted to his birth name of Booker DeWitt and had the Lutece twins transport him to Rapture, a reality where neither Anna nor Columbia existed. Elizabeth makes sure that Comstock is killed by a Big Daddy before she passes out. When she comes to, she finds Atlas has Sally and demands she help them escape the store to return to Rapture in exchange for her. As she sets out to do this, she is guided by visions of Booker, and later learns that she herself had died earlier in Rapture; she made a deal with the Lutece twins to combine all her quantum selves and memories of future time into one mortal body to return to this place at this time to rescue Sally, effectively leaving all alternate versions of herself in their own respective universes. She struggles with this, and further learns that Dr. Suchong of Rapture had worked with Jeremiah Fink from Columbia to collaborate on technology. Suchong forces her to briefly return to Columbia via a tear