Curley: I hate this waiting. I'd rather do anything but wait. That's one reason why I never got married.
Ricardo: Why are you here?
Nelson: Not to be a martyr.
Ricardo: I'm a patriot!
Nelson: And a fool!
According to the book Science Fiction Television Series, the scene where Farrell is dragged off to his death was nearly cut out. Despite the fact that Irwin Allen did not like personal dramatics, director Lenny Horn asked Joey Tata to play the scene straight--and they got away with it. Afterwards, Del Monroe told Tata "Holy ----, Joey...I got a terrible feeling watching that."
Henry Darrow is credited in this episode as Henry Delgado. He would shortly change his name to Darrow and star in The High Chapparal with Voyage alumni Mark Slade.
"Lethium" gas no doubt gets its name from Lethe, the river of Sleep and Forgetfulness, out of Greek and Roman mythology.