A mission of diplomacy brings the Enterprise to Elas to transport warrior leader Elaan (France Nuyen) to Troyius, where she is to marry into their society as the first step of bridging the two peoples and ending the long-lasting hostilities between them. The problem (or, more specifically, the running gag)—Elaan is a terrible-mannered woman from a society short on manners. She must be taught in the ways of etiquette. Her teacher (after she stabs the first one) is James T. Kirk, naturally.
Watchable, mostly brainless, middle-of-the-road fare, "Elaan of Troyius" is at its best when it shows Kirk balancing the approaches of diplomacy and forceful wording when dealing with the brat that Elaan is. Of course, the frustrating and repetitive joke of Elaan being so appalled at having to behave in a civilized manner is something that gets old quite fast, and it's not very wittily developed.
The episode turns into a mild muddle when it begins juggling mystical "love potion" (Elaan's tears) notions, Klingon battleship attacks, and mysteriously tensionless spy missions and sabotage, without really knowing which of the plots is important, or if any of it means anything when rolled into one. Still, seeing Kirk on the bridge while under the influence of uncontrollable love urges is somewhat amusing.