The Federation is in competition with the Klingons for an alliance with the inhabitants of Capella IV. The Capellans are a warrior tribe and there is dissension among them as to who to sign the mining rights treaty with. McCoy is familiar with their customs having once spent several months there. When a Capellan, who clearly favors the Klingons, stages a coup, Kirk, Spock and McCoy flee with the now dead leader's wife, who is about to give birth. Meanwhile, the Enterprise receives a distress call from a Federation vessel under attack and, with Scotty in command, leaves orbit.
Did You Know?
This is the only episode in which Uhura and Sulu call Scotty by his nickname. Otherwise, they call him "Mr. Scott". See more
About 28 minutes in (right after the rock-slide), Bones and Kirk are talking about the pregnancy. There are some sloppy audio cuts of Bones which were obviously put in after the scene was filmed, so his lips don't match up to the sound coming out. See more
Captain James T. Kirk
First of all, I must protest the killing of one of my crewmen.
If it was your man, was it not his privilege to die for you? I do not understand.
Their customs are different, Tier.
And different from those of my people, too, Tier. The sight of death frightens them.
Let me take this, Jim.
What Maab has said is true. Our customs ARE different. What the Klingon has said is unimportant and we do not hear his words.
[Capellans chuckle appreciatively
[whispering privately to Kirk