Sent to the planet Capella IV to negotiate a mining treaty with the warlike and tradition-bound people, Kirk and a party beam to the surface. Kirk finds that Klingon agent Kras has also arrived to negotiate a mining treaty with the Klingon Empire. Kirk and Kras negotiate with Teer Akaar, the leader of the tribes of Capella. Akaar favors the Federation while Maab, a highly influential Capellan, favors the Klingons. During a factional fight, Akaar is killed and Maab is installed as the new tribal leader. The landing party is imprisoned with Eleen, the pregnant widow of Akaar, and she prepares to be put to death according to custom.

Julie Newmar (Eleen)
Tige Andrews (Krag)
Michael Dante (Maab)
James Doohan (Lt. Cmdr. Montgomery Scott)
George Takei (Lt. Hikaru Sulu)
Nichelle Nichols (Lt. Uhura)
Cal Bolder (Keel)
Ben Gage (Teer Akaar)
Walter Koenig (Ensign Pavel Chekov)
Kirk Raymone (Duur)
Bob Bralver (Crewman Grant)

• McCoy previously visited Capella IV and briefs the crew on Capellan customs.
  
• "Red Shirt" Grant pulls his phaser when he sees the Klingon, and is promptly killed by the Capellans. (Apparently, no one thought to inform him of Capellan customs.)
  
• McCoy: "I'm a doctor, not an escalator."
  
• Eleen becomes Regent of Capella until her child, named Leonard James Akaar, can take over as Teer (leader).
  
• The Capellan double-vowels are prounced separately (e.g., Aka-Ar, Elee-En).