Christian Horn ( Cliff Robertson) is the leader of a small wagon train travelling from Ohio and headed for a new life for them in California in 1847. Instead, along the way, as with many others traversing long distances in search of a better life throughout history, they encounter hunger, thirst, disease, the elements, and hostile Indians. After reaching the scorching Arizona desert, all of his travelling companions, lacking Horn's determination, try to convince him to turn back. That his son appears to be dying is the straw that is about to break the camel's back for him. Still, in desperation, seeing a sand dune nearby, without seeing over it, he makes the trek over the rim, and encounters a whole new world, one which he never imagined, or for which he is not prepared. He is scared by a huge "monster" (a truck) and accidentally shoots himself, a minor wound. He meets a married couple, ownwers of a diner. The wife is a retired nurse's aid and treats his wound, then gives him a bottle of penicillin, something new to 1847 man. While beind treated, his sees a calendar, and the date 1961, meaning he has travelled a hundred yards and 114 years into the future. After reading his son's "future" in an encyclopedia, he realizes his ordeal is not without purpose, so he goes back over the rim, back to his own place and time, gives his son the life-saving medicine, and breathes new life into their journey. He is proud that the world that he briefly encountered was made possible by people like him and his travelling companions.
This episode, one of the series' best, reminds us that we should never give up. Perhaps more importantly, that we owe a debt of gratitude to those who braved the elements to make months and even years long journeys that enable us to today take only days or hours to travel, and make our world, the world Horn briefly glimpsed, possible. A tip of the hat to the Christian Horns of America's early days.