A dead girl, dressed in a tattered mermaid costume and a harpoon jutting from her chest, washes ashore on a world-renowned beach in Florida, bringing with it a nightmare of evil the City of Sarasota has never known. Chief Homicide Detective Miranda Morales, recently returned from a forced, yearlong sabbatical, leads the investigation that rocks the sedate arts and cultural mecca of the snowbirds who flock to the region in their lavish yachts and private jets, as well as the locals who resent the intrusion. When she and her devoted partner, Detective Matt Selva, arrive at the crime scene, the image of the dead girl transports her back to a time when she and her sister, as young children, would dress up like mermaids at their family's posh home on Longboat Key, and opens painful memories of her sister's decade-old suicide. Torn between duty and denial, she reluctantly attends a cocktail party hosted by her parents honoring the man who she'd hoped would propose. That decision catapults her into a world where people, unmasked, reveal a sordid underbelly of greed, power, obsession, and inhumanity, too close to home, unraveling a tapestry where all that glitters turns toxic, and deadly.