Trama

The Federation clashes with the Klingon Empire over mining rights to Capella IV. A sudden coup between its warrior-minded inhabitants forces Kirk's party to flee with the now dead leader's pregnant wife.

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.—garykmcd

The Enterprise is on a mission to a primitive, extremely warlike planet to negotiate a supply contract for a vital mineral. The party beaming down finds a Klingon has already gained the natives' trust; a crewman drawing his phaser is instantly killed. As the leader of their ten tribes hesitates which side to choose, there is a power-struggle and the Klingon's supporter takes over the throne, but respects Kirks military valor. Meanwile the Enterprise, incommunicado, learns an unarmed freighter is attacked by Klingons- Mr. Scott, in temporary command, leaves orbit to answer the distress call. McCoy touches a pregnant princess to diagnose her, and thus violates a taboo under pain of death- they manage to escape...—KGF Vissers

Te'er Aka'ar (Ben Gage) is the ruler of his people on a planet (Capella IV) rich in the mineral Topaline. Topaline is vital to the life-support systems of small planet colonies and is highly desired by the Klingons and the Federation. As a ruler of much courage, although he is old, Te'er Aka'ar is entitled to a young lovely wife to bear him a child, and his young bride is Ele'en (Julie Newmar). Meanwhile, the Federation is going to send a landing party to negotiate with these Capellans. They are learning by watching video that to the Capellans, combat is more important than love, and they are a very aggressive people. They are unaware at this time that the Klingons have been negotiating with Ma'ab (Michael Dante), the second most powerful man among the Capellans.

The Klingons, however, are not as fair as the Federation in negotiating. Kirk, Spock and McCoy beam down. Aka'ar wants to accept the Federation treaty, but Ma'ab leads an ambush to kill Aka'ar and the landing party as well as Aka'ar's lovely pregnant bride and the unborn child (so that Ma'ab can gain official control of the tribe and the planet). Klingon agent appeals to Ma'ab to kill Kirk and his men, but Ma'ab saw fear in the Klingon eyes and wants to negotiate with the Federation. In orbit, Chekov is tracking a unidentified vessel at the edge of their sensor range. Meanwhile Uhura picks up a distress call from a freight ship about being attacked by a Klingon cruiser. Scott has Sulu figure out the source and orders the Enterprise to leave orbit and save the Federation vessels.

Kirk, Spock and McCoy escape with Ele'en, who acts very high and mighty for someone whose life was spared (she wanted Kirk dead for touching the wife of a Teer during her escape). They found their communicators, but not their phasers. Aka'ar is now dead, but his unborn child, the heir, lives inside Ele'en, so the Klingon agent and Ma'ab's men (Ma'ab is now the leader) set off after the landing party and the young bride. Kirk and Spock work to find a good hiding spot and disrupt their pursuers by blocking off their paths by creating an avalanche of loose rock and debris..

Meanwhile the Enterprise realizes that it was a decoy distress call, designed to pull them away from the planet. Enterprise rushes back to Capella IV. As it returns the Klingon ship blocks its path and engages in battle. Enterprise beats the Klingon ship and reaches Capella IV Finally the young bride accepts McCoy's help, but not Kirk or Spock, and she only allows McCoy to touch her royal person. The child is born. It is a boy!! He is the heir. But Ma'ab and the Klingon still want to kill them all and they track them down. Ele'en knocks out McCoy with a rock and comes down to the foot of the mountain and tells Ma'ab she killed the child and all three of them as they slept.

The Klingon says "Don't believe her, we must check." Then Kirk and the others appear. The Klingon pulls out a phaser. Ma'ab realizes that this is dishonorable combat, so he gives instruction to one of his men who is carry a boomerang blade, the preferred weapon of the Capellans. Ma'ab stands high on a rock and yells "Klingon!!" at which point the Klingon kills Ma'ab with his phaser. Then Ma'ab's man kills the Klingon with the boomerang blade.

The child, the new king, was named Leonard James Akaar after McCoy and Kirk, and Ele'en would be the regent until the child comes of age. Eleen signs the mining treaty with the Federation.