After two outings heavily reliant on comic relief and having a lighter tone altogether, The Undiscovered Country comes in with the director of The Wrath Of Khan at hand and a much more political plot far easier to take seriously than anything involving whales or crazy cat ladies.
This was a return to form for the series which had become more cute and campy than legitimately involving sci-fi. Here we have what is basically the Cold War in space but with Shakespearian Klingons, sexy shape-shifting aliens and... Vulcan Kim Cattrall. All weird, wonderful stuff so far, I think you'll agree. This time, the overall tone mixes serious with playful much more convincingly and it never really goes too far one way or the other making this the most balanced Star Trek flick in a while. It has its fun moments with Kirk and McCoy having to deal with being unjustly exiled to some snow/desert planet and Uhura trying to get to grips with the Klingon language but it takes itself somewhat seriously and, most importantly, respects its audience a minimum. Kirk's sudden super-hate of Klingons feels a tad overdone as it's about 3 movies too late and weirdly unsubtle as a parallel for racism but otherwise, the plot won't piss you off quite as much as the last movie's did.
The Voyage Home was enjoyably zany, I guess, but there was very little space-set action going on, or anything non-whale-related going on for that matter, so it's good to see the Trek gang under solid direction, acting out a plot that's actually pretty intense and appropriately dramatic. Sadly, the main reveal proves to be deadly obvious but it hardly matters when the rest of the film is this enjoyable. Finally the cast aren't playing parodies of themselves and we're back in legitimate Star Trek territory. Christopher Plummer plays a one-eyed, Shakespeare-quoting Klingon in this and if that statement doesn't sound like the best thing ever to you then you should watch more movies. He's ever-so-slightly ridiculous but fun nonetheless. My favorite part of the film, however, would have to be the Kirk vs Kirk fight that occurs during his exile: it's classic Original Series material and is just as glorious as it sounds.
What this movie needed to make it a truly unforgettable outing is one or two heartbreaking dramatic moments. Something with an impact like the Enterprise exploding, Spock dying or even Data literally flying through space to save his Captain, just something to really put these guys in danger. This being the last official film with all the old gang, there would have been an opportunity there to have terrible things (or at least "big" things) happen to your favorite space crew. Still, it's good to see Sulu with his own starship, getting involved in the actual plot for once!
Overall, while not the best or the most memorable of Star Trek films, The Undiscovered Country is certainly a strong, respectable effort for the Original Series cast to retire on. It may not be an iconic movie but it's a good one, far better than its two predecessors (and its follow-up).