Logic and stoicism take thebackseat when Spock's mating instincts kick in, transforming him into a short-tempered mammal and compelling him to return to his home planet of Vulcan. Kirk risks all to help his first officer and pal fulfill his carnal urges. Once on Vulcan, however, Spoc still can't get a break - he is forced to fight his captain and his friend, unto the death.
The suspense in the storyline works well, as does the revelation of a side of Spock not normally seen. The planet Vulcan, with its glittering pebbles and red sky, vaguely reminiscent of Vegas desert, is a great match for the hot-blooded plot. Then there's tiny little T'Pau, with her Euro-Vulcan accent and mix-up of old Engish grammar (saying "thee" instead of "thou", etc.), all ready to kill Kirk and McCoy if one of them steps out of line. But the burgeoning loyalty between the trio is the plasma that holds the whole episode together.
Episodehighlights include the ends of the deadly lirpas breaking off like pieces of rock candy from a stick; the Vulcan ceremonial stand-ins shaking the bells like they're a part of the Salvation Army at Christmas; and the men talking at the end about whether Spock actually got lucky.
Then there's poor Nurse Chapel. She expresses her undying love through a bowl of plomik soup, only to have it literally thrown back in her face. When Spock's hormones get the better of him, he makes a half-hearted pass at her, which she reproaches, before nearly doing a dance of sheer delight at his request to make him more plomik soup. Shortly afterwards, her momentary glee turns to dismayed shock at glimpsing Spock's much younger, hotter bride. By the end of the episode, she must be totally confounded, as Spock is unattached, returned to his duties, yetdiffusedof those alarmingly exciting recent impulses.