• 
  Steven Mackintosh

  Narrator
• 
  Richard F. Haines

  Self - Chief Scientist, Narcap
• 
  Bruce Greenwood

   Narrator (3 episodes, 2013)
• 
  Anthony Mendez

   Antonio Zuleta / ... (3 episodes, 2013)
• 
  Grant Ross

   Police Officer (2 episodes, 2013-2014)
• 
  Chuck Zukowski

   Himself (3 episodes, 2013-2014)
• 
  J.J. Sicotte

   Himself (2 episodes, 2014)
• 
  Brandon Alvis

   Himself (2 episodes, 2014)

• 
  Lee Williams

  Narrator
• 
  Harry 'Doc' Kloor

  Self
• 
  Jeffrey Meldrum

  Self - Professor of Anthropology, Idaho State University
• 
  Keith McCloskey

  Self - Author, Mountain of the Dead
• 
  Phyllis Canion

  Self - Ranch owner
• 
  Ken Gerhard

  Self - Cryptozoologist (segment: Mexican Chupacabra)
• 
  Chris O'Brien

  Self - Author & Investigator

• 
  Chandra Wickramsinghe

  Self - Astrobiologist
• 
  George Simpson

  Self - Investigator
• 
  Malcolm Agley

  Self - Retired Police Constable
• 
  Yevgeny Anismov

  Self
• 
  Nick Pope

  Self - Ex British Ministry Of Defence
• 
  Robert Salas

  Self
• 
  Paul Stonehill

  Self - Journalist & Author