In the marshes of the Georgia Sea Islands, the death of a Southern matriarch hinges on the identity of her long-dead childhood maid. Lacy Cobb is just out of college, out of work, and out of luck. She's offered a job as a researcher by Clara Boundurant, the matriarch of Conway, on the coast of Georgia. Lacy meets with Clara, who wants to learn more about Hannah, a black housemaid from her childhood. Impulsive and at times recklessly obsessive, Lacy ultimately uncovers Hannah's identity and burial site in the Gullah community of Turtle Hock on Sargasso Island near Conway. Days after Lacy sends a copy of Hannah's death certificate to Clara, the old woman is murdered during an apparent break-in at her home. Lacy is quickly pulled into a vortex of conspiracy and intrigue when she returns to Turtle Hock to search for the connections between Clara's murder and the deep history of the ancient Gullah community. Joining forces with a newly-installed county sheriff from New Jersey, Lacy delves into a world of corrupt politicians, old-money privilege, a knife-wielding hit man, and the hunt for the one dead-true fact that will tie all the pieces of the mystery together.