Communication's officer Lieutenant Uhura sums up the decline and fall of the Roman Empire as the world knows it. The plot is really secondary. It's there to drive the story forward, but the underlying theme tells of the human condition via a reign of pure strength, and its ultimate failure.
This theme is reinforced by one of the supporting characters, an escaped 20th century Roman gladiator, Flavius, and his ultimate sacrifice. He represents the old way, once reformed, but gone back to the rule of Rome by fighting the Romans the only way he knows how.
The basic story is a rescue mission, but the real story is the heartfelt examination of the futility of a society that relies on a slave class to sustain itself on all levels, even down to bloody gladiatorial games as entertainment. Kirk is put through the rigors of experiencing both the pains and pleasures of such a society, and although he understands that he cannot change this world, he does help reinforce the message that will ultimately alter it and its Roman Empire on the most fundamental level.
Note Kirk's line as he talks to Flavius in the cave and pats him on the shoulder. Attach that to Uhura's summation at the end, and you got yourself the entire story: "It's not the sun up in the sky. It's the ..."
Positives; Kirk scores with a hot blonde. Druscilla is a HOTTIE! At least she was in 1967 :-) If I were the captain of the Enterprise I think I would bend the rules a little and beam her up to the ship before breaking orbit. Heck... I'd deserve it! The production values in this episode are also top notch. Largely because we're not dealing with aliens and spaceships here, but a historical retrofit to then modern times.
Excellent social commentary on not only a personal spiritual level, but also on the imperial nature of unbridled profit.
Enjoy.
