Rosalind Lutece

Rosalind Lutece is a quantum physicist in BioShock Infinite, who wrote books about scientific studies on alternate universes. She and her "twin brother" Robert guide Booker DeWitt through his adventures in Columbia to retrieve Elizabeth. From a young age, Rosalind was curious about the possibility of multiple realities and decided she wanted to be a physicist. Many years later, in the course of experimentation with atoms, she was able to indefinitely suspend an atom in midair. Her colleagues referred to the process as "quantum levitation", while Rosalind herself dubbed it the "Lutece Field". She began to wonder about the possibility of suspending larger objects, up to and including a city. At an indeterminate time, Rosalind met Zachary Hale Comstock, an influential religious figure who took great interest in her work. Comstock agreed to fund Rosalind's continued research into the Lutece Field in return for her help constructing a floating city which he had seen in a premonition. Continued experimentation with the Lutece Field led to Rosalind's first interaction with Robert Lutece, a male version of herself in an alternate reality. By manipulating a pair of quantum entangled atoms, the two were able to communicate across space-time barriers through Morse Code. When she reported this information to Comstock, he instructed her to find a way of accessing such alternate realities, which he believed would act as windows into prophecy. She and Robert then collaborated to make a contraption that allowed them to enter other realities via the Tears. Comstock would use the device extensively to see other realities and predict future happenings. He also later provided access to the Fink brothers, who had already been using Tears to advance technology and music in Columbia by decades. However, the device had an adverse effect on Comstock, aging him rapidly and rendering him sterile.