Sequel to: These rebel waves.

Held captive with the king's son in an endlessly shifting prison, Lu contemplates the violence of her military past to prevent the takeover of her island home, while a tormented Vex throws himself into the rebellion against Argrid forces.

As a child, Lu freed Grace Loray from King Elazar of Argrid. Now Elazar is holding her and his own son, Ben, captive in an endlessly shifting prison, forcing them to make a weapon that will guarantee Elazar's success in taking over the island. Vex failed to save Lu and Ben, and that torments him as much as his Shaking Sickness. The remaining free armies are allied with the stream raider syndicates, and getting them to cooperate against Argrid will take a strength Vex thought burned on a pyre six years ago. Ben knows he has to play his father's game of devotion to win this war. But how can a heretic prince defeat the Pious God? -- adapted from jacket.