Dedicate Initiates Rosethorn and Myrrhtide have been summoned to the Battle Islands because of problems with dying plants and poisoned water. Rosethorn decides that Evvy should come along too, to help her overcome lingering trauma from Gyongxe. And, as it turns out, what's going on in the Battle Islands is something only Evvy's magic can deal with.
- Continuity Nod: Nory is heavily implied to be the daughter of Pauha, the pirate queen from Tris's Book.
- A Day in the Limelight: This book is all about Evvy. In fact, it's the only Circle book in which the familiar quartet of Sandry, Tris, Daja and Briar don't appear.
- Jerk with a Heart of Gold: Myrrhtide, who Evvy calls "Fusspot", is rather high-strung but ultimately does care about people, doing his best to get the locals out of harm's way.
- Past Experience Nightmare: Evvy and Rosethorn both have nightmares of what they went through during the war in Gyongxe.
- Relocating the Explosion: In a rather unusual take on the trope, Evvy manages to relocate a volcanic eruption, thereby causing the birth of a new island, through a combination of persuasion, trickery and help from the spirits of other islands.
- Shell-Shocked Veteran: Evvy and Rosethorn are both traumatized by what they went through in Gyongxe.
- Simultaneous Arcs: This book takes place while Sandry, Daja, Tris and Briar are travelling to Namorn in The Will of the Empress.
- Taking the Veil: At the end, Evvy decides to become a novice at Winding Circle.
- Wake Up Fighting: Evvy attacks Myrrhtide once when he tries to wake her up because he disregarded Rosethorn's warning about not doing so because of what happened to her during the war.