Freedom's Ransom (Freedom Series, Book 4)

Enslaved on an uninhabited planet by the alien Eosi, Kristin Bjornsen and her fellow humans not only survived against all odds to colonize the world now known as Botany, but liberated themselves from their captors and claimed it as their home…
 
The colonists could not have achieved victory without the help of the exiled Catteni alien, Zainal, who helped Kris contact other races subjugated by the Eosi, and inspired the rebellion that freed them all. To ensure Botany?s future, its people must build alliances.
 
In the wake of alien devastation, Earth has been looted of its technology—technology Botany desperately needs. If Kris and Zainal can reclaim the stolen goods, they can assist Earth while setting a foundation for Botany?s place in the universe…