|First Air Date||:||2001-09-30|
|Last Air Date||:||2006-05-22|
|Number of Seasons||:||5|
|Number of Episodes||:||105|
Sydney Bristow, an agent who has been tricked to believe she is working for the U.S. government, is actually working for a criminal organization named the Alliance of Twelve. Upon learning this, Sydney becomes a double agent for the real CIA.