"Errand of Mercy" is the twenty-sixth episode of the first season of the American science fiction television series Star Trek.
The Klingon governor, Kor (played by John Colicos), would return in the Star Trek: The Animated Series episode "The Time Trap" voiced by James Doohan.
He would return again decades later in the Star Trek: Deep Space Nine episodes "Blood Oath", "The Sword of Kahless" and "Once More Unto the Breach".
Kirk appeals to Ayelborne, the head of the local council to allow the Federation to help them resist Klingon occupation, but the Organians adamantly oppose any use of violence.
When a Klingon fleet appears in orbit, Kirk orders the Enterprise to withdraw, which strands himself and Spock on the planet.
Kor has Spock questioned with a "mind sifter" device to confirm he is not a spy and designates Kirk as the Organian civilian liaison with the occupation force.
That evening, in an attempt to inspire the Organians, Spock and Kirk sabotage a munitions dump outside the town.
[12] The 1988 song "What's on Your Mind (Pure Energy)" by American synth-pop band Information Society uses a sample of Leonard Nimoy's voice from this episode.