Was author Erich von Däniken on to something when he suggested in the 1968 book "Chariots of the Gods?" that alien visitors came to Earth in ancient times? This History Channel series, with the cooperation of von Däniken, explores some of the author's most provocative theories, seeking out whatever evidence might verify the mind-blowing suggestion that we are─and were─not alone! 82 episodes on 23 discs. 69 hrs.