Cinder and her friends need to stop the royal wedding or the Evil Queen Levana will take over and destroy the Earth. She wants to marry Emporer Kai so she can steal the throne. Cinder is her biggest threat.
Cinder and her friends go up in space on the Rampion to get help from the Queen's programmer, Cress. She escapes from the Queen and goes with Cinder, while Cinder's friend Scarlet is kidnapped and taken to Luna, a colony on the moon.
The crew flies around the world, trying to make plans to stop Queen Levana. Everyone gets split up. Cinder goes to Africa and finds Dr.Erland to help her. The crew all end up going to the same place in Africa and reunite. They escape guards and fly to the palace on wedding day.
Cinder and her friends make it to the wedding on timme and hack the security system. They get Kai to secretly come on the ship with them. Cinder talks with him, and reveals that she is the true lost Princess Selene, rumored to have been killed by the Queen. They make plans to start a revolution on Luna to stop Levana forever.
The theme is to not give up. Cinder faced many difficult situations, but worked hard through them all. She only focuses on stopping Levena. Her friends get hurt, separated, and Levana is attacking back. Nothing will stop Cinder from giving up, and she eventually reaches her goal.