Groundbreaking first interracial kiss, otherwise a bad episode
Even though it was groundbreaking in the social sense, this episode was one of the worst in the series. The groundbreaking event was the first interracial kiss on network television that took place between Kirk and Uhura. However, it was so staged (apparently forced) and hidden that it is almost a non-event.
The premise is that there is a hidden colony of people with strong telekinetic power and their leader is ill. Therefore, they send for the Enterprise so that Dr. McCoy can treat and cure him. However, their power has made them extremely arrogant and they want Dr. McCoy to stay. When he refuses, they force Kirk and Spock to act like children, the worst scene is when Spock acts like a rearing horse.
The other redeeming feature of this episode is provided by Michael Dunn, the dwarf actor who is the only one on the planet without the telekinetic powers. He plays his role well and the Enterprise crew treats him as an equal, which strongly contrasts to his being a slave to the other people on the planet.
With so many possible plot scenarios that could have been used on Star Trek, it is unfortunate that the producers decided to feature some pathetic humanoids exhibiting some of the worst behaviors imaginable. It is such a forced story that the only reason I watch it is to try to determine if Kirk and Uhura actually put their lips together.

Most Underrated Episode
This is the most underappreciated episode of all, in large part because it is at times difficult to watch. A band of humanoids -- the Platonians -- have great telekenetic powers but are in need of a doctor. So, after luring the Enterprise, they humiliate and torture Kirk and Spock in an attempt to convince McCoy to stay. Later they beam down Nurse Chapel and Uhura (for that famous kiss) to join in the entertainment.

The payoff comes in the scenes with the dwarf Alexander, played by the great actor Michael Dunn. Alexander is the only Platonian without "the power." He is the court jester, the punchline of every joke, and feels himself inferior to all the other Platonians.

Kirk, Spock, and McCoy teach him otherwise. The abuse of power makes one a lesser, not a greater, being. We've heard that said before, but never so movingly. Shatner is at his best here. "Alexander," says Kirk, "where I come from, size, shape, and color don't matter. And no one has the power."

Pay attention to the ingenious metaphors and ironies. When Kirk, Spock, and McCoy first beam down, Alexander is seen around the corner where he casts a large shadow and seems at first to be a giant. Then there's the name "Alexander" itself, connoting greatness. The irony, of course, is that Alexander really is a bigger man than the small-minded Platonians, despite his small stature. In the end, Kirk triumphs, and Alexander declares to the tyrant, "Parmen, I could have had the power. But I refused to become like you."

A bit below average, if groundbreaking, episode
Another menacing and sadistic 3rd season episode, this time involving an Ancient Greek-like people
with telekenetic powers. This is one of those episodes-there would be many more ahead--that doesn't have a lot to say. It is most noteworthy for the kiss between Kirk and Uhura (too bad it had to be forced upon them), the absurdly camp antics performed by Kirk and Spock in particular, and the icy malevolence of Parmen and his cohorts. Whatever moral the episode conveys could probably best be summarized as "absolute power corrupts absolutely." There's nothing very deep about the crew's 'escape' either, although they are able to teach Alexander some valuable lessons before they go.

A few good laughs keeps this episode from being a dud
There's an evil man named Plato who wants to use the crew from the Enterprise as entertainment once Dr. McCoy and the others refuse to stay on the planet with Plato and the Platonians. The only defense that Captain Kirk, Dr. McCoy, and even Spock have is to try and not pay attention to the powers that Plato and his servants possess. But their powers are stronger than expected. Plato and his sidekicks have the power to make people do things they don't want to do by controlling their minds.

"Plato's Stepchildren" isn't that good of an episode, it's basically just an average episode at its best. However, there are a few hilarious parts that keep it from being a complete dud, such as when Plato makes Kirk and Spock dance around foolishly, and when Spock just can't quit laughing.

I recommend any fan of Star Trek to at least watch "Plato's Stepchildren."

Exploitation is wrong, and so is Shatner's acting
I've got to give the show and its fine crew of writers credit where credit is due, not just for the impact of Kirk and Uhura's kiss (the first interracial kiss in television history) but for their overall message in this episode.

With the help of the unimaginally indulgent, remorseless Platonians, they sent across a substantial message in a flash of sparkling outfits, thick makeup (particularly in poor Chris Chapel's case) and Will Shatner's staccato and over-the-top acting:

Exploitation is wrong.

True, this is a lesson we all learned years ago in Kindergarten with the Golden Rule, but, not surprisingly, in the midst of the guilty excitement of gossip and the build-'em-up, tear-'em-down philosophy of the media, we all tend to wander from that message.

The Platonians used Kirk, Spock, Uhura and Chapel, putting them into humiliating, and what would have inevitably become fatal, situations purely for their own amusement. One can find similar parallels in the mass media market today. Indeed we do seem to receive some sort of pleasure in seeing some of our favorite actors, writers, personalities, etc. put into embarrasing situations.

Kirk and the gang, as always, represent the new world of equality, virtue and harmony throughout, even when consumed with hatred for their capturs.

One has to wonder just who the Platonians represent.

One Schlocky Note: Shatner slapping himself silly, cracking the whip, and...well just *being* in the episode seemed to be one big campfest for him this time. Congratrulations Bill, you should be proud.