Sixteen-year-old Talullah Bridgestone has been home for three months when consequences of the Alteration show their true colors. She thought the voices of the Unforgiven would fade from her mind with time, but they've only grown stronger, more insistent. Her sisters and father are separating from their Ripples, the versions of themselves she knew in their other timeline. Soon, Talullah will be the only one who remembers that old life, and she fears those closest to her will feel more like strangers. When Talullah receives an invitation to study at the Still Currents Institute, she believes it's the opportunity she needs to fully banish the Unforgiven and learn how to live in her new reality. To be a new version of herself. One that can truly live in the present instead of obsessing about the past. But the school by the sea has secrets. An island legend, an elusive apparition, and a string of disappearances fuel Talullah's search for her necklace's lost sapphire. With it, she'll not only be able to rid her mind of its plague but also solve the island's mystery before anyone else disappears. Without it, she, too, might be forever lost by the sea.