An android, disguised as a Starfleet officer, takes control of the Enterprise and reunites its crew with an old friend ... everyone's favorite space pirate, Harcourt Fenton Mudd!
In a classic tribal plot, Mudd is now the imprisoned ruler of this planet of artificial beings, whose only purpose is to serve him. Having outlived the species that created them as servants, the near-immortal androids seek knowledge of humanity so that they may better serve. Seeking escape, Mudd has summoned Kirk and his crew to replace him.
Even a secondary explanation, such as Mudd's presence on the planet, is infused with fascinating and evocative thematic undercurrents. In this case, he was "pirating" stolen intellectual property, a subject more timely now than could ever have been in the time of its conception. Rightly so, as any modern exploration would necessitate more than a passing mention, as it is here.
Mudd proves a legitimate, succinct threat; his plan playing into both thematic substance as well as dynamic plotting. An always entertaining performance is backed by a thoroughly enjoyable structure. The setups and payoffs on every level are both textually effective and dramatically compelling. Humor and suspense cascade into each other in a seemingly effortless balance that defies standard camp.
The episode's concept is brimming with potent thematic conflicts. A "race" of beings with rigidly mechanical minds represent a causal, base logic. Connected to a central complex, they act as a passive-aggressive precursor to the ever popular Borg enemy. The themes they carry in opposition to the main crew are just as strong. They "understand to serve." Service leads to dependency, and in this way they are able to overtake worlds. They may offer eternal life, but it's still a cage. An artificial paradise of the nearly-eternal, removed from the human framework of time.
Freedom-loving Kirk is able to ultimately defeat their threat using his patented talking-to-death technique. Unlike other uses, however, this episode finds a more dynamic approach, enlisting the entire crew to perform contradictory loops of logic. It's a nonsensical ballet, hilariously incorporating the now well-established character personaes of the imprisoned crew.
As in the best of Trek, Kirk further defines humanity in opposition to the thematic makeup of the antagonists: the androids have no concept of play. (An essentially human attribute.) Within their strictly deterministic understanding, duplicity and illogical behavior does not compute. Further, in their service they seek purpose. A purposeless act cannot be reconciled. As in the highest philosophical drama, the conflict here is choice and choicelessness. Base, purposefully dictated action vs. playfully nonsensical free will.
As to the parade of lovely female servants Mudd creates to service his every desire?
"I am not programed to respond in that area."