The Inner Circle travels to the A Court of Mist and Fury Summer Court after Tarquin requests help investigating dangerous ancient magic destabilizing Adriata. But after days of searching, they find nothing except growing tension, violent power surges, and a High Lord who seems to be hiding something. When another uncontrolled burst of ancient magic shakes the city, the Inner Circle realizes the true danger may not be beneath Adriata at all—but someone within it.