Lacie Wagner has retreated to Nantucket to heal the physical and emotional scars of her fiery past. There, on the isolated island thirty miles out at sea, she finally feels safe, out of harm's way. But when she finds a female diver's body washed ashore, with her face destroyed beyond recognition, Lacie's tranquility is shattered. What starts out as the most explosive investigation of her career swiftly turns intensely personal.

A killer has chosen Lacie to tell his story, methodically releasing evidence, daring her to discover his identity - and the location of his last living captive. Stonewalled by high-ranking military officers and blocked by law enforcement at every turn, Lacie hires Nick St. James, a renegade manhunter who is as dangerous as the men he stalks. Together they run outside the law and straight into the heart of an unspeakable evil - a riptide that sweeps its victims one by one into the unfathomable depths of a watery grave.