- Deleted Scene: Another McCoy-Spock debate was filmed for this episode, but edited. Just before the landing party left the Yangs' flag room, Kirk cut short an argument which seems to be about nothing. The reason McCoy and Spock were arguing was cut from the episode. The dialogue excised from the final print was as follows (taken from the final draft shooting script for the episode):McCoy: Jim, the parallel's too close. They seem so completely Human. Is it possible that ?Kirk: The result of Earth's early space race?Spock: Quite possible, captain. They are aggressive enough to be Human.McCoy: Now listen, Spock, you
- A fairly lengthy scene from the final shooting script was edited from the final print of this episode. Soon after the landing party arrived on Omega IV, Kirk directly confronted Tracey about the possibility of his having violated the Prime Directive and Tracey attempted to defend his actions. Tracey also displayed open hostility towards Spock during this scene, revealing his dislike of Vulcans.
- Development Gag: Spock's supposed resemblance to the Devil from the Yang's "holy book" may be a reference to how some TV censors thought Spock's makeup made him look too "satanic".
- Magnum Opus Dissonance: At first, anyway. Gene Roddenberry thought this was his best work on TOS until that point, and even submitted the episode for Emmy consideration. In his later years, he came to realise just how clunky the story was.
- Money, Dear Boy: Gene Roddenberry selected this episode for the Viewmaster adaption because as the episode's writer, he'd earn royalties on it.
- Science Marches On: Captain Tracey thinks that the extended lifespan of the Omegans is due to a local disease, and hopes to isolate it and reproduce its benefits for other populations, but his hopes come to nothing after McCoy determines that the lifespan is the result of a genetic adaptation. Gene Roddenberry didn't foresee that a genetic adaptation allowing for long life would today be just as identifiable, and perhaps in the future just as reproducible, as a serum. Then again, there is the Federation's ban on genetic augmentation, which may still make the genetic adaptation legally useless, even if it's technologically possible to identify, reproduce, and transfer it.
- What Could Have Been:
- This script was originally in the running to be the second pilot for the show. Associate producer Robert Justman gently suggested to Roddenberry that he might want to hold it over until the show was actually commissioned, as the storyline (to put it mildly) didn't lend itself all that well to a pilot episode.
- When the series actually got underway, producer Gene L. Coon refused to use the story, which he considered to be flat-out ridiculous. It wasn't until late in the second season, when Coon had been replaced by John Meredyth Lucas and they were running low on usable scripts, that Roddenberry was able to push it through.
- The original 1965 script draft named the missing starship as the USS Argentina. The Enterprise landing party consisted of Kirk, Spock, a young navigator named Lieutenant Commander Piper, a helmsman called Lieutenant Phil Raintree, and the ship's doctor named Milton Perry. The latter two were killed during the actions on the surface. At the climax, Kirk fought Tracey in a western-style gunfight, during which Tracey shot Spock twice. However, he survived, because of the different anatomy of Vulcans (his heart not being in his chest). The first draft also featured a comic relief of the Enterprise computer having a female personality, an aspect which was eventually used in "Tomorrow is Yesterday".
Trivia / Star Trek S2 E23 "The Omega Glory"