It's usually taken as a given that Star Trek films from II to IV form a kind of a trilogy, but upon revisiting Star Trek VI: The Undiscovered Country (1991, directed by Nicholas Meyer), it becomes clear that that's not technically true. It is rather, a quartet. The Undiscovered Country acts as a capstone to the story begun by director Nicholas Meyer in The Wrath of Khan in a way that Star Trek IV does not. It resolves, among other things, Kirk's lifelong enmity with the Klingons, Spock's struggle with his human half, and the Federation's culture of perpetual war (long an odd element of a future envisioned as humankind on the advance). Like many Star Trek projects, this film is an allegory. Unlike some of Star Trek's other allegories, this one refrains from preaching by virtue including too many other interesting elements to distract the audience. It's a political thriller, and a submarine movie, and a prison movie, and a whodunit all rolled into one. This all serves the film as a clever disguise. It's also the most cinematically interesting Star Trek movie since the first one. Or, hell, maybe including the first one.
The story here finds the moon where the Klingon's manufacture most of their energy exploding at the outset of the movie, creating a humanitarian crisis for the Federation. Spock, at his father's request, has opened a dialogue with the head of the Klingon high command, Chancellor Gorkon, with an opportunity to declare an end to seventy years of hostility between the Federation and the Empire. Unfortunately, there are those on both sides of the Neutral Zone who would prefer a continuing state of war, and many in the Federation who feel that the Klingons can never be trusted. Kirk, still mourning the murder of his son in the third movie, is among the doubters. When Spock volunteers Kirk and the Enterprise as ambassadors to the peace talks, Kirk demures. "Only Nixon can go to China," Spock quips. "They are dying." Kirk replies: "Let them die."
The rest of the movie concerns an assassination plot aimed at Gorkon, and then at the head of the Federation at the peace talks. The Enterprise is framed for the murder of Gorkon, for which Kirk takes the fall as Spock and the crew race to uncover the true assassins. Kirk, for his part, is transported to a Klingon prison planet after a kangaroo show trial. He escapes, the conspirators are uncovered, and the plot is foiled in the end. I think I can safely give away the end of this movie. Does anyone really think that our heroes will fail in the end? No.
What's really interesting about this movie is the way it turns Kirk into Ethan Edwards. Kirk is certainly a John Wayne-ish part anyway, but this turn of events is a specific echo of Wayne's racist hero in The Searchers. Like Edwards, Kirk is a hero in spite of his racism. Part of his heroism in the movie is in overcoming that racism and doing the right thing. Kirk's inner turmoil here is actually well-handled even if the other racial allegories are ham-fisted. "Guess who's coming to dinner," quips Chekov, in one of the film's more obvious references. But before the whole thing becomes choked with its own self-importance, the game, as they say, is afoot and the film turns Sherlockian for a while. Then into a political thrills. And then the naval battle. One even forgets the racial allegory for a while, even as the political allegory (about the end of the Cold War) comes fully to the fore. In any event, it's a film that doesn't stop long enough to be pinned down.
This is the first film in the series that really thinks through its shot compositions in anything more than a strictly utilitarian manner. The blocking of scenes is important in this movie. This shot, for instance, shows the distance the film's plot puts between Kirk and Spock:
While the sequence where this shot occurs spins around Spock and Valeris in a slow, dizzy approximation of the way Spock rapes Valeris's brain to get the information he needs. It's one of the darkest scenes in Star Trek:
Star Trek VI also succeeds where the previous three films failed. It provides the audience with memorable villains. Christopher Plummer is a barnstormer as the Klingon general, Chiang. Nicholas Meyer lets the actor chew the scenery with relish after acquiescing to his request to forgo the hair piece that most Klingon's wear. Of all the Klingons who have crossed the big screen in the various Star Trek movies, Plummer is the one that stands out as an arch villain. It doesn't hurt that he's a Bardolator, spouting Shakespeare all through the movie. This is a honey glazed ham of a performance. Kim Catrall, on the other hand, is much more subtle as Valeris, the traitorous Vulcan. Catrall asked that the name "Eris" be worked into her name somehow, as both a signal of her true calling, and as a clue hidden in plain sight. Poe would have been proud. Meyer is canny about placing Valeris in interesting positions throughout the movie as a kind of gamesmanship with the plot, especially given that the early audiences would not ordinarily suspect that one of the villains was a Vulcan officer on the bridge of the Enterprise. It's a marvelous bit of misdirection. The audience is busy watching Plummer as Catrall worms her way under the skin.
Star Trek VI accomplishes at least one other thing. It allows the original cast the dignity of going out in style, in a legitimately good movie, rather than as laughingstocks in Shatner's vanity Trek. The cast deserved better than that ignominious fate, and this movie voids that indignity. This film feels very much like a valediction. When, at the end of the movie, Shatner/Kirk give the order to head for "The second star to the right, and straight on 'til morning," it's the send-off the original crew deserves.