Freedom Hold by Romana Drew

Kaylee’s dreams ended when the huge, furless Langons ordered her to marry Ralaf. If she refuses, she’ll be forced to work in the mine with all the other disposable Cadorie. Determined to find a better life, Kaylee runs away, searching for a mythical land called Freedom Hold, where Cadorie live free.
One hundred twenty years ago Langons invaded Cadorie. Although the League of Free Cadorie established an alien free zone called Freedom Hold, much of the world is under the thumb of the Langons. In the mining colonies, Cadorie are little more than slaves.

Kaylee meets Gillis, son of the head of the League of Free Cadorie. Together they plot to free Kaylee’s family and eventually their world. But that brings the wrath of the Langons down upon them.

It takes all of Gillis’ electronics knowledge and Kaylee’s mathematical skills to find a way to defeat the aliens infesting their world. In doi