text: Production D. C. Fontana recalled that once the show had been commissioned, she and the producers had a very short period of time to develop and produce the show before filming commenced. Additional footage was shot and inserted into the pilot, introducing the Atlanteans, who are the focus of Episode 2. The addition of these scenes resulted in quickly moving off-screen the characters of Paul, Eve and Jill. They were originally intended to be regulars, but the network wanted a more diverse set of travelers. A subplot involving the group finding an Air Force pilot from the 1940s, held prisoner by 16th-century pirates, was removed from the first episode as well.
  The character of Willoway was created with McDowall specifically in mind. The actor was interested, and took the role when it was offered.
  The show benefited from more location filming than usual, with familiar sites such as the Hollywood Hills, Zuma Beach, the Bonaventure Hotel in Los Angeles, and Griffith Observatory appearing in various episodes.
  Although it aired in a time when the nation's interest in the Bermuda Triangle, UFOs and fantasy was at a height, the show failed to find success. It was originally scheduled opposite The Waltons and Welcome Back, Kotter, both very popular family series, as a midseason replacement for another failed fantasy show in that time slot, Gemini Man. NBC would repeatedly preempt and move the series before finally giving up on it, after only ten of the twelve episodes that the network had ordered to follow the revised pilot had been produced. The script for an eleventh episode, "Romulus", has been circulated on the Internet.
  Within a few months of the abrupt end of production, several of the team that worked on the series would be producing the thematically similar Logan's Run for the 1977–1978 television season.