Peace negotiations have collapsed between the Federation and the warlike Klingon Empire. The Enterprise is ordered to protect Organia, a peaceful planet located near the Klingon border. Kirk and Spock beam to the surface to warn the Organians about the Klingons, but soon a Klingon fleet arrives, forcing the Enterprise to abandon the duo on the planet. The natives protect Kirk and Spock, even as Kor, the new Klingon governor, orders mass executions of the Organian people. As both Federation and Klingon fleets converge above the planet, Kirk and Spock execute a daring raid on the Klingon headquarters in an effort to destabilize their control over the planet.