The Last Blade Master was the fourth and final Adventures in Hyperspace book for which author Ryder Windham was contracted. However, the series was canceled after two books, leaving the third book completed in manuscript form, and the fourth as only an approved synopsis.
Han and Chewie are transporting an antique business droid, CZ-4—a gift from Boonda the Hutt to Jabba—when their hyperdrive malfunctions. They are forced to land the Falcon on a world inhabited by the Numm, humanoid aliens with primitive technology. The Numm are unable to provide the parts needed to repair the Falcon's hyperdrive. Rotten luck! The Numm become nervous at the sight of CZ-4, apparently because they are fearful of droids. While Han and Chewie consider their next move, CZ-4 goes missing. This is bad news because the droid is Boonda’s gift to Jabba. If they ever hope to do business with the Hutts again, they must recover the droid.
At first, Han and Chewie suspect that the Numm are responsible for taking the droid, but they soon discover that this moon has another population: a group of war droids who have been terrorizing the Numm ever since their ship crashed centuries ago. The war droids once fought on behalf of the Krath, a long-forgotten secret society that once menaced the galaxy.
It is the war droids who have abducted CZ-4. The war droids’ leader is known as the Blade Master (his arms house retractable metal swords), and he wants to cannibalize CZ-4 for parts. Chewbacca winds up competing against the Blade Master while Han rescues CZ-4 from disassembly. Chewie defeats the Blade Master. Han not only rescues CZ-4, but deactivates the other droids.
CZ-4 and Chewie figure out a way to quickly reprogram the remaining Krath droids to aid the Numm. The no-longer-threatened Numm are grateful to Han and Chewie, and lead them to the ruins of a crashed freighter (maybe the one that delivered the war droids to the planet). Chewie is able to salvage parts from the freighter’s wreckage, and uses these parts to repair the Falcon. Taking CZ-4, Han and Chewie are now able to continue on to Tatooine, where they deliver the droid to Jabba. Jabba tells them he has another job lined up for them.