First Season

Episodes:
1 - Rising (1)
2 - Rising (2)
3 - Hide and Seek
4 - Thirty-Eight Minutes
5 - Suspicion
6 - Childhood's End
7 - Poisoning the Well
8 - Underground
9 - Home
10 - The Storm (1)
11 - The Eye (2)
12 - The Defiant One
13 - Hot Zone
14 - Sanctuary
15 - Before I Sleep
16 - The Brotherhood
17 - Letters from Pegasus
18 - The Gift
19 - The Siege
20 - The Siege Part II

                                                        Second Season

Episodes:
21  Siege, Part 3 
22  The Intruder  
23  Runner   
24  Duet 
25  Condemned  
26  Trinity 
27  Instinct 
28  Conversion 
29  Aurora  
30  The Lost Boys (1)  
31  The Hive (2)  
32  Epiphany 
33  Critical Mass  
34  Grace Under Pressure   
35  The Tower  
36  The Long Goodbye   
37  Coup d'Etat  
38  Michael   
39  Inferno  
40  Allies (1)