The adventures of the bounty hunter's apprentice continue… Milo and his master Rod return from a dangerous quest to find a cure for a mysterious disease. They are the only hope for the sick people of the Underground. But as they return to the shores of Aetror, an unknown enemy takes Rod captive. As Milo struggles to find a way to set Rod free, he discovers that the disease was deliberately caused by a dangerous, powerful foe. Someone is determined to kill people of the Underground, and their methods are turning increasingly vicious. Milo is caught in the center of political conflict while trying to stop an enemy that is far more powerful than anything he has faced. With the help of several unlikely allies, Milo must outwit this enemy before his people are wiped out. Milo's courage is tested at every turn in this action-packed conclusion to the Underground of Aetror series.