| Name | First Aired | Runtime | Image | |
|---|---|---|---|---|
| S02E01 | Underground Apocalypse |
January 28, 2008
History
|
45 | |
| S02E02 | Vietnam |
February 4, 2008
History
|
45 | |
| S02E03 | A-Bomb Underground |
February 11, 2008
History
|
45 | |
| S02E04 | Viking Underground |
February 25, 2008
History
|
45 | |
| S02E05 | Hitler's Last Secret |
March 3, 2008
History
|
45 | |
| S02E06 | Maya Underground |
March 10, 2008
History
|
45 | |
| S02E07 | Mob Underground |
March 17, 2008
History
|
45 | |
| S02E08 |
Prophecies from Below
season finale
|
March 24, 2008
History
|
45 | |
| S02E09 | New York: Secret Societies |
March 31, 2008
History
|
45 | |
| S02E10 | Washington D.C.: Seat of Power |
April 15, 2008
History
|
45 | |
| S02E11 | Stalin's Secret Lair |
April 22, 2008
History
|
45 | |
| S02E12 | Katrina Underground |
April 29, 2008
History
|
45 | |
| S02E13 |
Secret Soviet Bases
season finale
|
May 5, 2008
History
|
45 |
No artwork of this type.
No artwork of this type.