The biggest surprise of this book to me was the absence of Emily Woo Zeller. Don't get me wrong, Cindy Kay did a stellar job, but I was used to Zeller's voice for this series.
Nyx and Zero are siblings now! Zero's parents adopted Nyx, officially. But Nyx is still unable to let her past as a space pirate go, she thinks that people talk about her behind her back and they don't really trust her.
Nyx sees a chance to redeem herself when Path Finder's (the ship Zero and his family came to Kaguya with) sister ship Dreamcatcher arrives at Kaguya and Nyx's family come with the ship. With the arrival of Dreamcatcher, it is revaled that Path Finder was only one ship among three other: Torchearer, Dreamcatcher, and Stargazer. The AI of Dreamcatcher and Stargazer were hacked, changing their time of arrival at Kaguya. As the adults are busy with preparing the colony for the arrival of Dreamcatcher's passengers, the kids find out that Nyx's family is after Stargazer, because they need one of these ships to escape from the little mining planet they are stuck at.
SPOILERS AHEAD
Zero realized that Stargazer is not far away, it is right there on Kaguya. They need to reach the Stargazer before Nyx's family. When they reach Stargazer, they learn that it landed on Kaguya 40 years ago, and the passengers of Stargazer survived there for all those years. A man declared himself king after the arrival of the ship, and he is making the Stargazer passangers suffer. Nyx's grandmother want to work with this king, while the kids want to save the Stargazer passengers from him and liberate them.
Zero learns how to befriend one of the dragons with a special frequency and with the help of the dragon, they are able to defeat the king and Nyx manages to convince her grandmother to turn herself in to the autorities of the colony.
Lastly, Zero realizes that the dragon wasn't his friend because of the special frequency, but because she (the dragon) simply liked him, which made the finale downright adorable, in my opinion.