Beneath the murky waters of the lake, an ancient being slumbers, and Brygida is its servant. Kept sheltered in the woods by her mothers from the nearby village, Brygida has never had so much as a friend—until the day she meets a charming stranger painting by the lake. He invites her to the village's harvest feast, but her taste of the forbidden ends with a murder.

Called into service for the first time, Brygida must take up her ancestral duty as Reaper of Death and solve the murder within three days. If she brings the murderer to the lake on the third day, the being she serves will be sated. If she fails, Brygida herself will be drawn beneath the murky waters, and the village massacred. There's only one problem: the main suspect is her charming painter, Kaspian.

As Brygida investigates, the dangers are many and answers few. The village and her family stand against her, and with time running short, the lake demands a price. Brygida believes Kaspian is innocent, but can she stake her life on it, when failure means condemning the rest of the village, and being dragged into the deep . . . ?