Ancient intelligences take up residence in the bodies of Enterprise crewmen. It’s supposed to be temporary…
Kirk and McCoy find themselves stranded on a planet where the Klingons are giving some natives help.
Captain Kirk goes full Ahab on a gas creature.
The Enterprise is safe from a murderous space probe as long as the probe continues to believe Kirk built it.
Spock has the return to Vulcan for unexpected reasons.
The dynamite team of Captain Kirk and Nurse Chapel deal with androids.
Is this the most infamous episode of the original series?