Season 4
The action explodes in the phenomenal fourth season when Sydney leaves the CIA to join a powerful new Black Ops unit, having no idea of the reunion in store for her.
Episodes
1 Authorized Personnel Only (1) Jan 5, 2005 
2 Authorized Personnel Only (2) Jan 5, 2005 
3 The Awful Truth Jan 12, 2005 
4 Ice Jan 19, 2005 
5 Welcome to Liberty Village Jan 26, 2005 
6 Nocturne Feb 9, 2005 
7 Détente Feb 16, 2005 
8 Echoes Feb 23, 2005 
9 A Man of His Word Mar 2, 2005 
10 The Index Mar 9, 2005 
11 The Road Home Mar 16, 2005 
12 The Orphan Mar 23, 2005 
13 Tuesday Mar 30, 2005 
14 Nightingale Apr 6, 2005 
15 Pandora Apr 13, 2005 
16 Another Mister Sloane Apr 20, 2005 
17 A Clean Conscience Apr 27, 2005 
18 Mirage May 4, 2005 
19 In Dreams... May 11, 2005 
20 The Descent May 18, 2005 
21 Search and Rescue May 18, 2005 
22 Before the Flood May 25, 2005