A look at what could cause once-thriving groups of people to just abandon their great cities, never to return; modern scientific knowledge may be able to help answer the unsolved questions surrounding these lost civilizations.
| Name | Type | Role | |
|---|---|---|---|
| Brian Leff | Writer | ||
| Buddy Whitaker | Writer | ||
| Kevin Burns | Writer | ||
| Rob O'Brien | Writer | ||
| Buddy Whitaker | Producer | ||
| William Shatner | Host | ||
| John Brandenburg | Guest Star | Self - Theoretical Physicist | |
| Edwin 'Ed' Barnhart | Guest Star | Self - Director, Maya Exploration Center | |
| Dr. Travis Taylor | Guest Star | Self - Astrophysicist | |
| Paul Springer | Guest Star | Self - Prof. of Comparative Military Studies, U.S. Air Force | |
| David Whitehead | Guest Star | Self - Investigative Journalist/Radio Host | |
| Paul Bahn | Guest Star | Self - Archaeologist | |
| Tok Thompson | Guest Star | Self - Assoc. Professor of Anthropology, USC | |
| Jonathan Young | Guest Star | Self - Founding Curator, Joseph Campbell Archives | |
| Andrew Collins | Guest Star | Self - Author, Beneath the Pyramids | |
| Amir Hussain | Guest Star | Self - Prof. of Theological Studies, LMU | |
| Carl Wendt | Guest Star | Self - Prof. Archaeology, CSU Fullerton | |
| Rob Weiner | Guest Star | Self - Dept. of Anthropology, Univ. of Colorado, Boulder | |
| Kim Egan | Executive Producer | ||
| Anthony Fiorino | Executive Producer | ||
| Kevin Burns | Executive Producer | ||
| William Shatner | Executive Producer | ||
| Susan E. Leventhal | Executive Producer | for HISTORY | |
| Rob O'Brien | Executive Producer |