The crew of the Enterprise arrives at Omicron Ceti III expecting to find a ghost town of sorts. The human colonists there have been exposed to Berthold rays, a form of radiation exposure to which for a few weeks will result in death. Instead, the colonists are alive and well. If anything, they are thriving, at least physically. They've even regenerated lost organs!
Intellectually, however, they seem a little fat, dumb and happy. And the Enterprise's crew soon finds out why. It appears spores from certain flowers on the planet, when inhaled, not only protect those exposed from the effects of Berthold rays but also grant them a high degree of physical robustness. However, you can't get something for nothing and in exchange for a little extra zip in their step, those exposed to the spores end up being a bunch of sybarites.
Spock is amongst the first Enterprise crewmen to be infected, led to his doom by the lovely Leila Kalomi, whom he had known back on Earth. Having failed at winning Spock's heart six years ago, the resourceful Leila turns to the spores to seduce the normally stoic half-Vulcanian (in these early episodes, this is how people from Vulcan are described).
After exposure to the spores, Spock declares his love for Leila, they lock lips and I don't know what happens next but suffice it to say, when next we see Spock, he's wearing the one-piece uniform favored by the colonists, his Starfleet uniform nowhere to be seen (perhaps it needed to be laundered after the passionate goings-on which occurred after the kiss).
While Spock turns into a bit of a Lothario after exposure to the spores, McCoy turns into a caricature of a Southern gentleman, his normally subdued Southern accent slipping its leash and a mint julep his constant companion.
Even Kirk eventually succumbs to the spores, but being Kirk, it takes two doses to turn him into one of the pod people.
At this point, we get a glimpse of a rarely seen side of Kirk, that of the vainglorious officer. After turning into a lotus-eater, Kirk goes back to his quarters on the Enterprise to pack up some things before he joins the colonists (and the rest of his crew) on the idyllic paradise that is Omicron Ceti III.
What does he pack?
What does he intend to bring with him on his exile on Eden?
His Starfleet dress uniforms and his decorations.
He even fondly strokes his decorations and one would be pardoned for expecting him to start whispering: “My precious...my precious...”
Like I said, it's a side of Kirk we haven't seen before and it seems a bit uncharacteristic of the Kirk we all know and love.
Even more jarring is how he shakes Spock out of his hedonistic state of mind after he, himself, serendipitously (and somewhat miraculously) manages to nullify the effects of the spores simply by getting angry (which, given the effect of the spores on a person's state of mind, is, as I mentioned before, miraculous).
He unleashes upon his first officer, his best friend, a torrent of bigoted and racist vitriol, insulting his half-human/half-Vulcan (excuse me, half-Vulcanian) heritage and taunts him for having the nerve to woo the deliciously Aryan Leila.
The purpose of this is to anger Spock enough to free him from the nasty bout of happiness he's suffering.
Frankly, it's a little hard to stomach.
Kirk later claims that it hurt him to have to say what he said but to this viewer, he seemed a wee bit too enthusiastic during his tirade.
Frankly, I don't know what the point of this episode was.
Perhaps it was an thinly veiled allegory against drug abuse?
An indictment of the mindless adherence to any school of thought, be it political or religious?
Frankly, I don't know.
What I do know is that the sad thing about this episode is not that Spock got a taste of happiness and then walked away from it.
It's that amongst the entire crew of the Enterprise, only Kirk couldn't find it in himself to actually embrace happiness, if only for a brief moment.