"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.
When Lokai demands the death of Bele, Kirk orders both of them to be taken to the ship's brig, but a force field generated by both aliens makes that impossible.
The distinction is lost on the ship's officers, who query whether the original Cheronians were monochromatic like the crew of the Enterprise, and leave the legal matter for authorities at the next starbase to decide, as the Federation has no extradition treaties with Cheron, and the case requires due process.
Once the Ariannus mission is completed, Bele takes control of the Enterprise again, this time disabling the self-destruct system.
[2] The look of the aliens Bele and Lokai was decided only a week before filming began, based on an offhand comment by director Jud Taylor.
[3] The script evolved from an outline by Barry Trivers[4] for a possible first season episode called "A Portrait in Black and White".
They did find some redeeming moments, such as the climactic chase to the ruined planet's surface and Gorshin's performance as Bele.
[10] In 2017, ScreenRant ranked "Let That Be Your Last Battlefield" the 7th most optimistic episode of Star Trek television, pointing out the crew's reaction at the end.
[15] On March 22nd,1981 this episode was released on CED VideoDisc, with "The City on the Edge of Forever" on the flip side of the disc.
This episode was released in Japan on December 21, 1993 as part of the complete season 3 LaserDisc set, Star Trek: Original Series log.3.