Her friend Will, however, has to feign happiness, keeping his unrequited love for her to himself. Sydney now finds herself facing a moral dilemma: What does she want from the rest of her life, and what does she tell her friends and would-be fiancee.

Sydney's SD-6 partner, Dixon, a devoted family man, warns her not to reveal her secret to Danny, and Sydney knows that SD-6 leader Sloane would not look kindly on any breach of security. Even Marshall, SD-6's highly inventive weapons and gadget maker -- and a super intelligent man with noticeably lacking social skills -- knows that divulging their identities is strictly verboten. This is the one rule you don't break.

When Sydney breaks protocol and tells Danny about her secret life, her world is spun terrifyingly sideways: Danny's life is placed in mortal danger, and Sydney is in a fight for her own life. She discovers that her long-estranged father, Jack is also SD-6 and that the organisation is covering up a nefarious plan - they are not a branch of the CIA, but are actually an enemy of the United States. With nowhere else to turn, Sydney seeks the aid of the real CIA in hopes of putting SD-6 out of business.

She is put under the command of operations officer Vaughn who enlists Sydney to become a double agent. Her mission is to complete her cases at SD-6 while reporting her findings back to the CIA. But when Sydney finds out that her father is also affiliated with the CIA, she begins to question where his true allegiances really lie.