Even as Darth Vader and his Imperial garrison approach Mimban from the air, Luke and Leia find that their biggest problems lie under the planet's crust. For deep in the soil lives Mimban's deadliest predator—perhaps the galaxy's deadliest predator—the gigantic, wormlike wandrella; and if the humongous wandrella can't catch them, the subterranean race of aboriginals—the Coway—just might!
Luke and Leia manage to simultaneously evade the wandrella and lure it to its death by hiding in a Thrella well. However, the monster's destruction of the ladder that they used to get into the well forces the pair to temporarily split up from Halla, Hin, Kee, R2-D2 and C-3PO. After agreeing to meet up with the rest, Luke and Leia venture into the planet's subterranean levels.
Meanwhile, Darth Vader lands on Mimban, drawn by the report on the presence of Luke and Leia on the planet, as well as that of the legendary Kaiburr crystal. He takes charge of Grammel's troops and begins the search for the pair.
Luke and Leia eventually find Halla and the others captured by a tribe of Coway. In order to free the others, Luke must prove himself in single combat with the tribe's greatest warrior or be killed by the tribe along with the others. The fight goes badly for Luke, and he ends up with his face held underwater by the Coway warrior.
The comic adaptation of Splinter of the Mind's Eye remained fairly faithful to its source material. Because of the requirements of the format and the limited space in which to tell the story, a number of elements were either altered or omitted. The departures from the book included:
- The scene showing Darth Vader demanding a status report from Captain Piett never appeared in the book. It contains a possible continuity error, since Luke and Leia are on Circarpous V and Vader is asking Piett how long it will be until the Executor is within the orbit of Circarpous IV. However, it is possible that Vader believed that going directly to Circarpous V might inadvertently alert the Circarpousians to the presence of the Empire's illegal energy mining operation on that planet.
- In the book, when Luke reaches the end of the ladder in the Thrella Well, he discovers a ledge, steps onto it and informs Leia of his discovery. In the comic, Leia is the one to discover the ledge.
- In the book, while the wandrella pokes its head into the well, Luke discovers that he has lost his blaster pistol. Before he and Leia discover the well in the comic, Luke tells her that he lost his blaster pistol when he leapt from the swamp crawler.
- When Halla is asked about the Coway by Luke and Leia in the book, Halla says that little is known about them, but they are "not the least bit subservient." She then appears to conjecture that the Coway are "shy and peaceful." In the comic, Halla says that the Coway's relation to the "Greenie" Mimbanites means that they are "shy and peaceful," but adds that not much is known about them. When Halla, the droids and the Yuzzem leave the well's opening, Halla tells C-3PO that she lied to Luke and Leia about the Coway because they would be too scared by the truth to go any further.
- When Luke and Leia discover the underground lake, Luke thinks of the darkness of the water as being as black as the inside of the Emperor's mind. In the comic, Leia voices this sentiment.
- Another scene that does not appear in the book shows Halla, the Yuzzem and the droids sitting around a campfire. It segues into Vader's arrival on Mimban as Halla mistakes his shuttle for a shooting star. The last scene that doesn't appear in the book shows Halla and the others being captured by the Coway.
- Splinter of the Mind's Eye (TPB)
- Star Wars: 30th Anniversary Collection Volume 8: Splinter of the Mind's Eye
- Star Wars Omnibus: Early Victories
- Star Wars: Luke Skywalker, Last Hope for the Galaxy
- Star Wars Legends Epic Collection: The Rebellion Vol. 5
- Star Wars Legends: The Rebellion Omnibus Vol. 2