In the season one episode "Errand of Mercy", a war is declared against what alien species?
Answer Klingons
The first episode in which Klingons appear in the Star Trek universe, "Errand of Mercy" starts right off with starting a war. Kirk and Spock attempt to persuade a peaceful planet to resist Klingon invasion in the episode, which introduced the Enterprise's greatest enemy alien race.
Asked by Ben Jenkins · Last updated 2 years ago · 35.7K views
