“Let That Be Your Last Battlefield” is the fifteenth episode of the third season of the original American science fiction television show Star Trek. Written by Oliver Crawford (based on a story by Gene L. Coon, writing under his pen name "Lee Cronin") and directed by Jud Taylor, it was first broadcast January 10, 1969. In the episode, the Enterprise encounters two survivors of a war-torn planet, each half black and half white (though on opposite sides from each other), each committed to destroying the other. The episode guest-stars Lou Antonio and Frank Gorshin. Plot The Federation starship Enterprise is on a mission to help decontaminate the polluted atmosphere of the planet Ariannus, when sensors detect a Federation shuttlecraft that was reported stolen. The craft is brought aboard along with its alien pilot, who identifies himself as Lokai, a political refugee from the planet Cheron. Lokai's most striking feature is that his skin is ink-black on the left side of his body and chalk-white on the right side. Shortly thereafter, sensors detect another spacecraft in pursuit of the Enterprise. The alien craft disintegrates, but not before its pilot, Bele, transports to the Enterprise bridge. He is colored black and white, but directly opposite to Lokai, being black on the right side and white on the left side. Bele explains that he is on a mission to retrieve political traitors. His current quarry is Lokai, whom he has been chasing for 50,000 Earth years. Bele is taken to Lokai, and the two begin to argue about the history of their peoples, including whether it was justified for Bele's people to dominate Lokai's people; the two men almost come to blows. Bele demands that Captain Kirk take him and Lokai to Cheron. Kirk refuses, telling him he will have to make his case to Federation authorities. Some time later, the ship changes course to Cheron, and Bele announces that his "will" has taken control of the ship. Lokai demands the death of Bele, and Kirk orders both of them to be taken to the brig. Unfortunately, a force field generated by both aliens makes that impossible. With no other way to regain control, Kirk threatens to destroy the Enterprise, and begins the ship’s auto-destruct sequence. In the last seconds of the countdown, Bele relents, and the ship resumes its course to Ariannus. As Bele continues angrily to press his matter with Starfleet,