Splinter of the Mind's Eye was written by author Alan Dean Foster, who had previously ghostwritten the novelization of the original Star Wars (now known as Episode IV A New Hope) whilst the film was still in production. Star Wars was a gamble for George Lucas. There had not been a science fiction movie quite like it before and there was no guarantee that it would be a success. The effects facility, Industrial Light & Magic, was not making good progress and Lucas began to believe that he would be lucky if his film made its money back. Splinter of the Mind's Eye was seen by Lucas as the story for a potential sequel film if Star Wars had not performed so well at the box office and become the cultural phenomenon we all know and love.

Lucas wanted Splinter to be able to be turned into a low-budget movie and presumed that Harrison Ford would not want to reprise his role as Han Solo. Foster was told to avoid including any space battles or other scenes that would require expensive special effects. He decided to limit the story to the surface of one planet and a simple "quest" story trope.

Luke Skywalker and Princess Leia, accompanied by R2-D2 and C-3PO, are travelling to Circarpous IV for a Rebel Underground meeting. Their ships encounter an energy storm that forces them to crash-land on Mimban, a swamp planet and home to one of the Empire's secret energy mines.

In a local tavern of the mining town, they meet an old woman called Halla, who claims to be a master of The Force. They learn that Halla is searching for the "Kaiburr crystal" which can magnify Force powers (in the current Star Wars canon, "kyber crystals" are the power source for lightsabers). It is located in the Temple of Pomojema, deep in the swamplands. She enlists Luke and Leia's help, agreeing to get them off-world if they help her find it. When Darth Vader learns of the crystal and its powers, he sets off to Mimban to find the temple and it becomes a race to obtain the artefact first.

Lucas wanted Luke and Leia to constantly be getting chased and told Foster to throw them from one perilous situation to another. Foster obliges by having them thrown into an Imperial prison for unintentionally starting a brawl, getting attacked by a giant worm (a "Wandrella") in the swamplands and finding an underground city, where they are stalked and captured by Mimban's primitive humanoid natives, the Coway. To save his colleagues, Luke fights and defeats the Coway's champion fighter in hand-to-hand combat. This reflects the intention for Luke to develop more as a warrior in this story which is something that there was not enough time for in the original movie.

Compared to the big-budget and critically-acclaimed sequel movie, "The Empire Strikes Back", Splinter is quite a mediocre story. It was the first novel in the Star Wars "Expanded Universe" and the true continuation of the Star Wars story for a short period before Empire's release. Although Splinter also features a confrontation between Luke and Vader in its finale, there is no hint of Darth being Luke's father. In addition, the romantic tension between Luke and Leia continues throughout the book which is rather awkward considering that they were discovered to be brother and sister in the original trilogy movies. All this serves to sever Splinter from the official Star Wars canon (either pre or post-Disney) and make it into a bit of an oddity.

Splinter is elevated when viewed through the lens of nostalgic affection and knowledgeable Star Wars fans will appreciate that its main story beats were suggested by Lucas himself. Thanks to Foster's solid and competent writing style and the presence of many beloved characters, Splinter ends up being a pleasant stand-alone curio for all those interested in the Star Wars universe.