May the fourth be with you (tomorrow). Have you heard the apocryphal tale of Splinter of the Mind's Eye?
When I first heard about Splinter of the Mind's Eye, it was as the mythical, proposed fallback-sequel to Star Wars that would have been made in the event that Star Wars had not been the run-away hit that it turned out to be. Everyone online speaks of this book as an exciting alternate universe that might have been: the Star Wars 2 we might have ended up with, had the first not been such a huge hit that ESB and ROTJ were written and produced.
And indeed, if you research a little about what Lucas himself was saying to the press back in the late 70s and early 80s, you can see plainly that Lucas was still formulating what this hit movie he'd made would become. It's easy to forget, now that the episode numbers have been added, that the original theatrical version of Star Wars was a single movie, with no episode number to suggest prequels or sequels, and that Luke and Leia and Han had little to no story than exactly what was either on the screen or in the novelization.
I stumbled across a copy of Splinter of the Mind's Eye in a used book store whilst on holiday in Oamaru, in New Zealand. I couldn't very well put my holiday on hold to sit and read the book, so I stuffed it in a suitcase and tried vainly to forget that I had it and that it had to be read. As soon as possible.
When I got back home, I excitedly started the book, with expectations of startling new story directions, unresolvable story twists, and far, out-of-canon character developments. It turns out, like the time I finally got to play D&D only to discover that despite my parents' warnings, it did NOT bestow me with actual magickal powers of the occult, that the hype I had heard was a little misleading.
Don't get me wrong: Splinter of the Mind's Eye is a good sci fi book. It's even a good Star Wars book and, but for a few details, actually fits neatly into even the post-modern prequel-ravaged canon. The story is pretty simple. To avoid spoilers, here's a paraphrase of the back-cover summary: Luke and Leia crash land on a planet and get caught up in a treasure hunt for some important artifacts called Kaiburr crystals, a sort of natural Force-enhancer, eventually encountering Darth Vader himself.
It's a very entertaining book, and maybe twice as much now as it would have been before the prequels, for me at least, because it's the old Star Wars universe, the one before Star Wars got muddled with painfully verbose back-stories and far more lore than it can bear. In a way, this book allows franchise-weary fans to return to simpler times, back when the lore was hazy and populated more by your own imagination than by proscribed canon ardently defended by fanatics. I like a Star Wars universe where I can imagine elements from my own whimsy, the way I did back when I would stare at my lunchbox, or bed sheets, or shelf of action figures, and dream up stories about the little details in the art work, without giving a second thought to what the official keepers of continuity have to say. In a way, this book isn't the mythical back-up script in case of failure, but a back-up Star Wars universe in case the original is spoilt by too much commercial success (it's funny to say that Star Wars has only just recently been spoilt by commercial success, but I guess there are degrees of everything).
This story picks up neatly where Star Wars leaves off, so this book can, more or less, fit in as an Expanded Universe story taking place between the first and second movies. The only problems a die-hard canon-fanatic might have are with little details like the fact that a random lady has some grasp of The Force (enough to coach Luke, in fact), and that Leia brandishes a lightsaber and fights Vader, and that Vader doesn't really seem to use the Force much and even gets hit by a blaster bolt. Let's face it, though; canon-fans can, if they want to, explain minor anomalies like that away quicker than Qui Gon can take a midi-chlorian reading.
There's a definite budding romance between Luke and Leia in the book. It's not super comfortable trying to fit that into the established universe, but like it or not, that's what Lucas created. Luke thinks a lot about Leia and how beautiful she is and how he hopes that she can come to see him as more than just a commoner, and their flirtatious wrestling sparks an important plot point. I do get the sense that there was absolutely NO kernel of the idea that Luke and Leia could be related in this book; instead, it definitely reads like the continuation of what everyone assumed was going to be a long, drawn out will-they-or-won't-they romantic subplot. I don't think Lucas had the notion that they were related, either. Heck, I'm not even sure that he had that notion even in ESB.
Looking at the book objectively as a historical artifact is also interesting:
Luke and Leia crash land on a swamp planet in this book.
Luke crash lands on the swamp world of Dagobah in ESB.
Luke finds an older Force user, who becomes a mentor (of sorts), in this book.
Luke finds Yoda, a jedi master, in ESB
Vader apparently has no Force-block of blaster fire (as he has in ESB)
In the book, Luke and Leia defeat the local influx of Imperial troopers by first becoming captives of, and then befriending, a local tribal population.
That's also what Leia does in ROTJ
C3PO shows no sign of being a linguistics expert in this book.
C3PO is primarily a translator in ROTJ
Ben Kenobi makes no appearance in this book whatever (vocal, ghost, or otherwise)
Kenobi pops up as a Force ghost in ESB and ROTJ
However you take the book, it's a solid read. It's by no means the alternate Star Wars as it could have been that the Internet assured me it would be, but it's a fun story set in the old Star Wars universe that still hadn't quite nailed down all the rules to how things worked or who was related to whom. Worth a read, and I don't care what anyone says, for me it's the official and only Star Wars sequel.