The Kassa gambit

"Centuries after the ecological collapse of Earth, humanity has spread among the stars. Under the governance of the League, our endless need for resources has driven us to colonize hundreds of planets, all of them devoid of other sentient life. Humanity is apparently alone in the universe. Then comes the sudden, brutal decimation of Kassa, a small farming planet, by a mysterious attacker. The few survivors send out a desperate plea for aid, which is answered by two unlikely rescuers. Prudence Falling is the young captain of a tramp freighter. She and her ragtag crew have been on the run and…