Nora was the identical twin sister of Rowan Mills, her junior by only 3 minutes. While Rowan was happy and outgoing, Nora was more introverted and had trouble fitting in. As a child, Nora was molested by an uncle. While Rowan grew up normally and eventually got a job as a data engineer at QuanCord Analytics, Nora studied marksmanship and got a job at a private security firm active in the Middle East. At one point, she tried to pressure Rowan into using her access at work to help her spy on competing security firms. When she refused, Nora assaulted her. During her next assignment in Iraq, Nora's team was hit by an IED and attacked by insurgents. She survived, but was abducted and taken to Mosul. After 3 months in captivity, she escaped and returned to the States. Angry at Rowan for turning out so well, Nora killed her. As a result, she suffered a dissociative identity disorder, her personality being split between herself and Rowan, whom she spent most of her daily life as. Rowan's body was hidden in a freezer at their mother's house.
Afterwards, Nora became a legendary hacker known in certain cycles as "Lord Baltimore". Using her own computer skills and Rowan's job access, she specialized in searching more or less public records, such as social networks and bank records, as well as the deep web for cyber-skiptracing. After using her cybertech skills to locate her targets, she used her military training to bring them in.
During their investigation, Elizabeth Keen and her team exposed Nora's split personality. Her original personality could only be brought forth by making her listen to the Ink Spots song "We Three", which she had heard the night of Rowan's murder.