简要：Sidney Bristol is a college student who has an unusual job - she is a spy working for the Central Intelligence Agency under secret conditions, and even her friends don't know what she is doing. When her boyfriend proposed to her and told him what she did, her employer followed the procedure and killed him. Sydney decided to leave the organization before they also killed her, and she realized that she had actually been working for SD6, a mysterious criminal organization worldwide. Sydney joined the Central Intelligence Agency as a dual agent, helping CIA agent Vaughn shoot down SD6. She discovered that her father was another double agent in SD6, working together. When carrying out tasks to uncover the work of Prophet Rambaldi, she must provide feedback to the Central Intelligence Agency and not reveal her secrets.
