Having woken up in Hong Kong, with no memory for the last two years (!), Sydney returns to Los Angeles to try to piece together the last two years of her life and discove ...

Sydney's search for her past leads to an imprisoned Sark, but their QandA is cut short when he becomes the ransom for a pair of abducted CIA scientists by the Covenant, w ...

Sydney and Vaughn are reunited again as a team to prevent Sark, now a head leader of the Covenant, from destroying the nation's satellite communications system. Meanwhile ...

Sydney discovers a link to her missing two years in the form of Simon Walker, the dangerous leader of a group determined on retrieving deadly biological weapons. Meanwhil ...

While Vaughn's life hangs in the balance, Lauren butts heads with Sydney after learning the part she played in his stabbing. Meanwhile, Sydney further questions Sloane's ...

Sydney's emotions are turned inside-out when she once again comes face-to-face with Allison Doren, the murdered Francie's doppelgänger, who was presumed dead but is now ...

Jack takes drastic measures to ensure that the NSC never finds out the truth about Sydney's murder of the Russian diplomat Lazarey. But, his actions place a heavy strain ...

When Sydney is taken into custody by the NSC honcho Mr. Lindsey, Jack and Vaughn have no choice but to ally themselves with Sloane to rescue her. But with only hours to s ...

After making a shocking discovery of a severed human hand in the desert that belonged to Lazarey, the Russian diplomat she murdered while working as a brainwashed assassi ...

The identity of the mysterious St. Aidan forces Sydney to pull a stunned Will Tippin out of witness protection for help in finding Lazarey to clear her name. But the purs ...

In this episode, Sydney finally learns the shocking truth about her missing two years from an unlikely source: FBI Special Officer Kendall. Kendall whisks her away and ta ...

Jack contacts a mysterious woman, that of former KGB agent Katya Derevko, Irina's older sister, to help him free Sydney and Vaughn, whose plane has crashed inside North K ...

Sydney and Vaughn are sent to retrieve the Doleac Agenda to gain an advantage over The Covenant. For this, Sydney and Weiss must convince rogue security systems designer ...

While trying to retrieve a bomb, Sydney and Vaughn are ambushed by unidentified assailants. Meanwhile, Lauren and Sark continue to solidify their new partnership as the n ...

Sydney and Vaughn must convince bomb maker Daniel Ryan that they are part of The Covenant in order to find out where he has hidden one of his devices. But Sydney discover ...

Sydney attempts to rescue Dixon's kids after they are kidnapped by Sark. Meanwhile, Lauren's status as a double agent for the CIA and the Covenant is put to the test when ...

Sydney and Vaughn must track Kazari Bomani down to get hold of a piece of the Rambaldi puzzle before the Covenant gets their hands on it. Meanwhile, Jack reveals his susp ...

Sydney and Jack warn a disbelieving Vaughn about their suspicions of Lauren being the CIA mole. Meanwhile, Kazari Bomani and Sark take possession of the Rambaldi machine ...

After finding out that Lauren really is working for the Covenant, Vaughn is told by Jack and Sydney to keep up the facade of a happy marriage in order to keep tabs on his ...

After finally discovering the identity of the Rambaldi Passenger, who is Sloane's illegitimate daughter, Sydney and Jack seek the aid of Sloane, to track the Passenger do ...

With the aid of Katya Derevko and CIA imprisoned security systems designer Toni Cummings, Sydney and Vaughn attempt to track down Sloane and Nadia. But Lauren and Sark ar ...

Lauren stages a stunning betrayal by impersonating Sydney and blowing up the CIA offices to steal classified materials, and nearly killing Marshall in the process. But Sa ...