The Prime Directive has what TV Tropes calls a “broken base”: is it a good concept that is rarely explored properly, or is it a concept that always ruins any story focusing on it. I’m a believer in the former, and this is an example of a story that explores it correctly. It’s also my favorite Klingon episode.
For those who don’t know, here’s how the prime directive works: if a Starfleet starship encounters a society that has yet to develop warp technology, they cannot interfere with it. They can only observe the society. Why does this law exist. First, the society could become dependent on the Federation as they learn how to use technology, preventing them from functioning on their own. Or the society could have an unfair advantage and subjugate weaker societies.
The episode takes place on the planet Neural, which apparently Kirk has visited before, because he’s friends with Tyree, the leader of the Hill People. He notes that the people only use bows and arrows, but to his surprise, he sees a tribe using flintlock rifles. Spock is shot and has to be taken to sick bay. Bones and Kirk return and blend in, discovering Klingons are supplying people with rifles. Kirk is attacked by a mugato (I’ll admit the mugato does look silly by today’s standards, but I often dismiss things like that) and it poisons him. It is here that we meet Nona, a seductive woman who is attempting to temp Tyree into negotiating with the Klingons in order to get their rifles. She heals Kirk with a ritual, saying that now he is hers. Kirk and McCoy argue about whether the Hill people should be given rifles as this would violate the Prime Directive. Later, Kirk is attacked again and this time uses a phaser, which Nona steals. However, Tyree’s enemies are more interested in her than the phaser. When Tyree, Kirk, and McCoy come to her rescue, Tyree’s enemies suspect that it’s a trap and kill her. This makes Tyree mad for revenge. Kirk reluctantly realizes that he must now provide, as he puts it, “serpents for the Garden of Eden.”
In a way, this episode is often seen as analogous to the Vietnam War, with the two warring societies representing the two forces involved in that conflict. What I like best about the episode is the uncertainty of its ending. War is not something that can realistically be resolved quickly. Kirk is put in a Morton’s Fork, and this is a realistic resolution. I feel it truly is one of Star Trek’s best stories.