Season 2
Episodes
1 Underground Apocalypse Jan 28, 2008 
2 Vietnam Feb 4, 2008 
3 A-Bomb Underground Feb 11, 2008 
4 Viking Underground Feb 25, 2008 
5 Hitler's Last Secret Mar 3, 2008 
6 Maya Underground Mar 10, 2008 
7 Mob Underground Mar 17, 2008 
8 Prophecies From Below Mar 24, 2008 
9 New York: Secret Societies Mar 31, 2008 
10 Washington D.C.: Seat of Power Apr 14, 2008 
11 Stalin's Secret Lair Apr 21, 2008 
12 Katrina Underground Apr 28, 2008 
13 Secret Soviet Bases May 5, 2008