Sea Castle

The fourth installment in Mayne’s “Underwater Investigation Unit” series (following Sea Storm) features Sloan McPherson, a police diver for the Florida Department of Law Enforcement Underwater Investigation Unit. Sloan’s unit has been temporarily disbanded for political reasons, and she has been assigned to another department in the interim, but her diving skills are called upon when a woman’s body is found on a Florida beach, and her belongings are seen floating offshore. Local police want to call the death a suicide, but Sloan doesn’t agree. She approaches Gwen Wylder, a notoriously prickly homicide detective, for help. In return, she reviews a cold case for Gwen, turning up new evidence and solving the crime. Meanwhile, Gwen finds connections between the woman on the beach and other suspicious deaths in the area, suggesting that a serial killer may be on the loose. Narrator Susannah Jones skillfully conveys the intricacies of Mayne’s complex plot, which chillingly delves into the psyche of a serial killer. Jones creates a variety of engaging character voices, keeping listeners wholly invested in the story.