A jealous telepath may doom Spock.
So, a group of children take over the Enterprise because of course they do…
The Enterprise visits a planet like Earth except the Roman Empire never ended.
A computer running the Enterprise may lead to a lot of dead people.
Captain Kirk teaches a valuable lesson to some nascent Americans.
Kirk, Uhura, and Chekov find themselves forced into the role of gladiators!
Tribbles eat, reproduce, and cause all kinds of trouble.
Harry Mudd causes more problems for Captain Kirk, this time with a planet full of androids.
It is easier for a civilized man to pose as a barbarian than it is for barbarians to pose as civilized men.
The Enterprise is safe from a murderous space probe as long as the probe continues to believe Kirk built it.