Huck Jones, the son of the admiral of the Soaker fleet, has a legacy to live up to. Haunted by the distorted memories of his mother's untimely death, he must face his demons and the man who raised him as he strives to take the courageous step forward into manhood. When he's transferred to the worst-performing ship in the fleet, everything he believes is called into question when he meets a lowly brown-skinned bilge rat girl. Huck walks a deadly rope.

Meanwhile, Sadie, destined to be a Rider in the Stormer army, seeks to avenge her brother's death at the hands of the Soakers. Trained hard by her mother, an experienced Rider, Sadie knows strength and determination more than most. Her father, a Man of Wisdom, has shown his cowardice more times than she can count. As her world and family fall apart, she must cast aside her anger and focus on the wisdom she's always brushed off as foolishness.

Amidst everything, a plague ravages all, discriminating against no one.

When four worlds collide, lines will be drawn, sides will be chosen, victory will be sought. Death will be wrought. The mysteries of the cure for the deadly plague will be uncovered. Who will survive? And what will those who do learn about themselves and the ones they love?