Alias (2001)

For seven years, Sydney Bristow (Jennifer Garner) believed she was working for a covert branch of the C.I.A., named SD-6. However, when she tells her fiancé of her job, Arvin Sloane (Ron Rifkin), head of SD-6, and an old family friend, has him murdered. With this life-shattering event, Sydney learns not only that SD-6 is a mercenary group of terrorists, but that her father, too, works for SD-6. Sydney then works with the C.I.A. as a double agent, trying to bring down SD-6 with her father, a second double. This is only the beginning of a path of betrayal, murder, lies, and disbelief. Sydney Bristow pushes through trials of love, learns the truth about her mother, loses a friend in an utter form of incredulity, pitfalls herself into months of torture and puzzlement, and is tormented with countless revelations to come.