Originally airing from 1977 to 1982, Leonard Nimoy (famed for his role as Spock in the original Star Trek series) hosted this 30 minute (23 minute actual run-time) documentary television show devoted to mysterious phenomena, legends, conspiracy theories, as well as other curiosities and intrigues.
In 2002, an eight episode revival was hosted by Mitch Pileggi (known for his role as FBI Assistant Director, Walter Skinner in the science-fiction, supernatural series X-Files).
History Channel has revived the show for a 60 minute slot (approx. 43 min. run-time) for 2018 starring Zachary Quinto (similarly cast as Spock in contemporary Star Trek movies) as host