 Sydney Bristow is a college student who leads a double life: she works for SD-6 which supposes to be a branch of the CIA. Recently fiancéed, she tells her boyfriend the truth. The next day, he is murdered. And Sydney s father tells the truth: he is a double agent for the real CIA, as SD-6 is a renegade agency who alledgedly killed Sydney s fiancé. Sydney must take a decision upon which revenge and justice will haunt her upon the rest of her life...