Blonde bombshell Rebecca Hall had always been the top student of her class. At the age of 8, she was enrolled in Ms. Stacy's Home for Gifted Children. Her parents, Janelle and Steve Hall, had always stressed the importance of education. During Rebecca's valedictorian speech, Janelle fell ill and quickly died the next morning. At her mother's death bed, Rebecca promised her mom that she'd make her proud.
After becoming a CIA agent, Rebecca learned of her parent's involvement with Kelsi Dagger's experimentation incident. While not major characters in the series, Janelle and Steve Halls were the head surgeons in Ms. Dagger's experimental operation. This discovery motivated Rebecca to overthrow "Lady X".
A normally conservative Rebecca makes bold attempts throughout the show to try and increase her chances of becoming head CIA agent.
Although Rebecca keeps her relations with Gustavo Cerati strictly professional, she has developed an intense but unrequited love for him.