In Search of...

This series was created after the success of three one-hour documentaries produced by creator Alan Landsburg: "In Search of Ancient Astronauts" (1973) (based on the 1968 book and the movie "Chariots of the Gods?" (1970) by Erich von Daniken), "In Search of Ancient Mysteries" (1974), and "The Outer Space Connection" (1975) (later adapted into popular paperbacks written by Landsburg), most of which featured narration by Rod Serling, who was the initial choice to host the spin-off series. Serling died before production started, and Leonard Nimoy was then selected to be the host. The series was revived in 2002 with host Mitch Pileggi and again in 2018 with Zachary Quinto for the History Channel.