Hilde Highbranch is a squirrel princess, ready to rule a kingdom carved out of the Harper’s Isle by the long ships, torches, and axes of her mother’s warriors.

Finbar the Pale is a young fox thief, scavenging what he can to survive in the cluttered streets of Murk Pool, a bustling Harper’s Isle port town.

Rose is a rat orphan, adopted by the monks of the hidden island monastery of Io Abbey and raised in the faith of holy saints.

All their lives are about to change.

Hilde’s aunt, the scheming Gudrid, shatters the peace of the Harper’s Isle with a shocking act of betrayal. Aided by the white-cloaked, fanatic Ashborn Squirrels, Gudrid slaughters Hilde’s family and takes her throne. With Finbar’s help, Hilde escapes and seeks shelter with Rose on Io Abbey—then enlists her new friends in her quest for vengeance.

To avenge her family, Hilde, Finbar, and Rose will travel across stormy seas inhabited by monsters, brave a lawless coastal outpost, and search a tangled forest for a Wolf Witch. They’ll need allies—a quick-tongued squirrel skald, a mad hyena alchemist, and a determined otter rebel. But as Hilde’s quest throws the Harper’s Isle into turmoil and sets her against her own gods, she must ask herself a terrible question: what is she willing to sacrifice to win—and what will be left when her battle is over?