Sonata in Orionis - Earth Song, #2

Five hundred years have passed, and Earth is but a distant memory, a story told to children. Bellatrix is humanity's home now, as well as its future. When the alien race responsible for mankind's rescue returned, humanity found that its rescue came at a price-it had to serve its alien masters to repay that act, and the Chosen were formed. Minu is the daughter of the First Among the Chosen. While she wants to follow in her father's footsteps, very few women are Chosen.
When her father goes missing, though, it's her only opportunity to find out what happened to him. But the galaxy is a dangerous place, as humanity has already learned, and there are many races that would bring about our downfall. Our sonata is quickly coming to its end. Will we learn to survive, or will we perish like so many other races have? Minu holds the key to our survival.and our annihilation.