Every Trek film featuring the original show's cast has a different tone, from hard science fiction to goofy comedy. This one's a political thriller, and its release, exactly three weeks before the fall of the Soviet Union, was even more timely than the filmmakers intended. Directed by Nicholas Meyer, one of the most reliable names in the franchise, this is a solidly written and filmed production, with a few genuinely terrific visuals. But it's the cast that sells it. They knew it was their swan song, and every one of them gave it their all. The enthusiasm is infectious, and it serves to elevate an already decent sci-fi film. In my opinion, this is only the fourth best film of the franchise, but out of thirteen (so far) that's not too bad, especially for a cast that'd been at it for 25 years.