Niles Townsend is a private detective, and a struggling survivor of supernatural violence. With his eye on retirement, he takes one final case, recovering a box of stolen mementos for architectural Wunderkind Carter Bennet. In short order, Niles falls in love with his new client, that new client is kidnapped, and violence and the supernatural are back on the menu. So much for retirement. With the help of an assassin, the search for Carter leads Niles to an immigrant gang from rogue nation Sel Souris and their illicit trade in a drug made from ground beetles found only on their island. Niles is unaware that his past lives link him to the colonial history of Sel Souris, and that he was instrumental in the destruction of their island's numinous and strange magic. Of this magic, only the beetles remain as a hopeful flicker. Sleeping Underwater explores the legacy of trauma, tracing scars travelling down one life into the next. Niles Townsend is about to learn that some mysteries can never be understood, and that love, even illegal love, is powerful enough to reach inside and heal, no matter how far we've withdrawn from the world.