The Deadly Years
A mysterious radiation causes crew members to age rapidly. The pushy Commodore Stocker insists on taking command from the failing Kirk, and charges through the Romulan Neutral Zone.
We've always found this one funnier than perhaps intended, probably since all our characters' traits are exaggerated and simplified as they head into old age. A good premise, but not much is done with it. Another meddling commodore, another trial against Kirk, and even the lame-o Corbomite Maneuver returns. (We clearly overestimated their intelligence.) The captain's usual stubbornness increases to where it overrides his better judgment. Spock is alarmed by his loss of abilities, and McCoy is most amusing as a short-tempered, finger-waving crank. It's also strange that while the aging make-up is rather good, none of the actors looked this way when they really did reach their golden years. Kirk seems to lack any interest in his old flame, who as it happens is attracted to older men. The friction between Kirk and Spock is more painful than Dr. Wallace's unrequited love, but they are at least united by a common enemy from Starfleet's woefully incompetent upper ranks. Youth and vigor are regained in the nick of time, and order is restored.
Spock Saves the Day: Spock corrects Kirk when he slips, presides over the trial, and works with McCoy and Wallace to prepare the adrenaline cure.
Oops: Spock's okay, but McCoy calls him "Spwawnck."
Developments: Spock is more perceptive of his mounting physiological weaknesses than the human crew members, and is especially concerned about his slipping mental faculties. His long lifespan and preference for much warmer environments is also emphasized. There would be some logic in relieving Kirk's command and taking over, but Spock doesn't have the "heart." He does protest the commodore, but to no avail. As with any fight between Kirk and Spock, this one doesn't last.