Splinter of the Mind’s Eye often pops up when people complain about contradictions in the Expanded Universe.
However, people perhaps aren’t noticing the publishing date. Splinter of the Mind’s Eye was written before The Empire Strikes Back, and is the story Lucas considered doing if Star Wars initial movie had not made enough for the rest of the movies. The ‘official’ Expanded Universe did not begin until a decade later.
The story tells of one of Luke and Leia’s adventures. En route to convince planetary leaders to support the Alliance, they are forced to crash land on the wild world of Mimban. The muddy swamp hides an Imperial mining colony. They sneak into the colony searching for a way offworld and encounter Halla, a Force Sensitive who has found out about a treasure: the Kaiburr Crystal, which increases the Force power of the user. Figuring out they are not locals, they reach an agreement, help her find the crystal and she helps them escape the planet. Unfortunately, they are side tracked and taken prisoner by the Imperials, who fortunately have no idea who they have. Not so fortunately, the Imperial in charge calls higher authorities…and word reaches Darth Vader.
There are some serious misconceptions taking place about this book. The biggest one is that Luke and Leia had an incestuous relationship here. In fact, the closest they come is Luke watching Leia sleep and being tempted to kiss her. In fact, most of their behavior, after the movies, comes across very much like sibling squabbles. Luke’s temptation to kiss her is no more contradictory than the kiss she gave him in A New Hope for luck, before the swing across the chasm, or her kiss in Empire in an obvious attempt to annoy Han. There is certainly no evidence of anything physical beyond that. And at the time, neither knew of their relationship. Alan Dean Foster’s style isn’t toward romantic encounters in detail in any case. Nor is it common at all In Universe to detail physical romantic encounters.
A Dark Horse Comics graphic novel adaptation of this book basically skips the whole temptation bit, and adds in Admiral Piett and a mention of Vader thinking of Luke as his son. This brings it more in line with the rest of the Expanded Universe and movies.
Splinter of the Mind’s Eye is considered part of the Star Wars Expanded Universe canon, and the worlds of Circourpous (the intended destination) and Mimban are mentioned elsewhere, as are the aliens involved. Both Halla and the Kaiburr crystal go largely unmentioned elsewhere, except the brief factoid that Luke tested a piece of the crystal in a lightsaber and that the powers of the crystal diminish the farther it is from its temple. The kaiburr crystal (yes that was the spelling) was mentioned in early drafts of the scripts in the Making of Star Wars books.
Consistency with the later published official canon:
Leia kissing Luke did happen in the movies, as I mentioned before. Once for luck, once to make Han Solo jealous. Nothing in the book goes beyond that.
Obi-Wan apparently directing Luke’s actions is a reasonable link to the movies. While his Force ghost does not appear, Luke instinctively replies once ‘I’m Ben Kenobi’ when fighting Vader and more than once ponders how he sometimes feels someone else directing his actions. Given Obi-Wan’s earlier speaking to him and later appearance in the movies, this is believable that he was helping guide Luke’s Force connection. In later stories such as Allegiance, by Timothy Zahn, Obi-Wan directly gives him advice and directions.
Darth Vader, while appearing a bit ‘off’ from his movie appearance with his ‘toying’ with the heroes is actually also consistent with later stories. As Anakin, he toys with his enemies in Approaching Storm (also by Alan Dean Foster). He also has a tendency to pursue other objects like the Kaiburr crystal, including the Bota entrusted to Jax Pavan in the Coruscant Knights series, as well as a special stone Anakin himself had given Jax. He also pursued the Murr Talisman in the Empire/Rebellion era comic series in the Vector cross over. His harshness with subordinates that fail him is legendary, the only difference here being he uses his lightsaber rather than the Force Choke.
Leia picks up Luke’s lightsaber and fights Vader at one point in this. Given no one knew Leia was Luke’s sister at this point, it makes it an unintentional but welcome hint that maybe the Force is with her. Leia’s Jedi training doesn’t come until the stories after Return of the Jedi, starting at Heir to the Empire but interrupted repeatedly until the Dark Nest Crisis by Troy Denning when she completes it. Leia also flies a Y-Wing in this, suggesting her skills as a pilot. And in later Dark Horse comics she is again shown flying a fighter.
Artoo and Threepio also are in the story, with their usual bantering. While its likely a coincidence, it’s perhaps a foreshadowing one that Vader is able to simply turn them off at one point. This could be due to simply his skill with droids and machines, subconscious recognition on his part, or even some command leftover from their ownership by Anakin that kicked into play. A coincidence almost certainly…but one that fits.