One of the more iconic episode from TOS, and rightfully so. It’s also full of firsts. It the first episode to feature Walter Koenig as Chekov, the first to bill DeForest Kelley alongside William Shatner and Leonard Nimoy in the opening credits, and perhaps most importantly, the first to feature Gerald Fried’s iconic “battle music”.
 The episode… it examines the estrangement of arranged marriages by a traditional society, and the lengths the parties involved will go to to alter the bargain made in which they had no say.
 Nimoy does a fantastic job in this episode showing off a wide range of emotion, something normally not asked of him.
-Excerpts from IMDB reviews
Even though it was not the first ep filmed for S2, it was the first one that was aired on TV. This also marks the first visit to the planet Vulcan, and the first time we get so see other Vulcans (beside Spock). Vulcans were named for Roddenberry’s concept for their planet being a “volcanic”, desert world. We hear the Vulcan phrases: “Peace and long life” and “Live long and prosper” accompanied by the hand salute (which Nimoy modified from a gesture made by Jewish priests).
Mr. Spock is NOT himself, as he is acting illogical and irate (even throwing the plomeek soup that Nurse Chapel brings him against a wall)! FYI: This soup stained the set for several weeks. He insists that the Enterprise be diverted to his home planet- Vulcan- for shore leave (which he never takes). Spock finally reveals to Capt. Kirk that these behavioral aberration happen every 7 yrs when Vulcans must mate (pon farr) or die! Nurse Chapel comes to see Spock in his quarters, worried about his condition (esp. b/c she is in love w/ him). They get a brief scene (where he probably senses that she has feelings for him) and we learn that Vulcans also dream.
In one of the best scenes of this ep, Kirk disobeys Starfleet orders out of friendship; as he explains to McCoy, Spock has saved his life many times. There is another great scene in the turbolift w/ where Spock requests Kirk to accompany him down to the planet, as a close friend; then here is a pause and he asks McCoy the same thing. Kirk and McCoy think they’re about to be be in roles of “best men” at the wedding ceremony, but there is much more involved. As a viewer commented, the final scenes are Shakespearean.