Freedom series (Anne McCaffrey)

Kristin Bjornsen lived a normal life, right up until the day the Catteni ships floated into view above Denver. Now, as human slaves are herded into the maw of a massive vessel, Kristin realizes that her normal life is over, and her fight for freedom is just beginning.

In Freedom's Landing, a galactic invasion forced thousands of humans to colonize a new planet. In Freedom's Choice, human Kris Bjornsen and her comrades found new hope for rebellion. Now, in Freedom's Challenge, Kris and her Catteni lover Zainal prepare to face danger and pain, in the final fight for liberty. To safeguard his family & his freedom, Zainal must lead an attack on his own planet.