The Enterprise is being visited by the Pandronian commander Ari Bn Bem, who is an
independent observer. He accompanies a landing party on a mission to a newly
discovered planet, but, instead of observing, he interferes with the mission.
Before long, Kirk and his people are captured. Then they encounter a powerful
alien entity who insists they leave the planet.
David Gerrold, writer of the Original Series episode "The Trouble With Tribbles" also penned this episode.