This episode was expanded to become the first half of a full-length novel by science-fiction author Alan Dean Foster as Star Trek Log Ten.

Set in the 23rd century, the series follows the adventures of Captain James T. Kirk (voiced by William Shatner) and the crew of the Starfleet starship Enterprise.

In this episode, while traveling by shuttlecraft, several Enterprise crew members are captured and have to use their individual strengths to prevent a powerful alien weapon from falling into the wrong hands.

Producer D. C. Fontana approached Larry Niven in 1973 to see if he would write an episode for The Animated Series, suggesting that he might adapt one of his existing stories.

The story involved a group of Outsiders who were using a quantum black hole to disable passing ships drives' in order to pirate them.

The original male and female starship crew were replaced by Sulu and Uhura, while the small spacecraft became the newly introduced long-range shuttlecraft.

That the Kzinti's clothing and ships were depicted in shades of pink was long rumored to be due to director Hal Sutherland suffering colorblindness,[6][7][8] but this was contradicted by Bob Kline, Filmation designer and layout artist, who stated in a podcast interview that the color choices were the work of color stylist Irv Kaplan.

[6] This is the first Star Trek story broadcast (in either its live-action or animated incarnations) in which James T. Kirk (William Shatner) does not appear, although his voice is heard in the standard opening credits.

"The Borderland of Sol" was developed from his original pitch for The Animated Series and was first published in Analog magazine in January 1975, and republished in the collection Tales of Known Space in the same year.

[citation needed] Niven later wrote a storyline in the syndicated Star Trek newspaper comic strip entitled "The Wristwatch Plantation", which re-introduced the Kzinti to that universe once more.

"[14] A CGI animated film called Star Trek: Lions of the Night was in development by writer Jimmy Diggs at the time, which would have had Captain Hikaru Sulu attempting to prevent a Kzinti invasion of the Federation using the USS Enterprise (NCC-1701-B).