Balance of Power — Kenneth McDonald

In this thrilling conclusion to the “Refugees of the Crucible” trilogy, planetary exploration and space battles combine in a deadly race against time to stop a nearly invincible intruder from another galaxy. For centuries, the descendants of a lost human colony ship lived on the icy world Crucible, the unwitting subjects of an alien AI's research project. Led by spacer Kevan “Mac” McDougal, the colonists finally managed to defeat first the AI and then a spawnship of the insectoid K'rakk interested in stealing its technology. With their connection to the greater universe restored, Mac and Lessa McDougal have left their former prison behind them and relocated to Epsilon Station. But when a massive alien ship equipped with the same power-dampening technology enters the galaxy and starts destroying the fleets and colonies of the League of Allied Systems, the McDougals must join a desperate effort to uncover the secrets left hidden on Crucible before it is too late.