In the dark world of the relentless .40 Caliber Killer, FBI super-profiler Agent Meredeth Connelly fights to stop him before he massacres another family. As she meticulously collects evidence and the body count rises, it becomes clear that this ruthless murderer knows her intimately. Each nauseating crime scene evokes a mounting sense of dread, each dead child intensifies her emotional anguish, her senseless feelings of guilt, and her unbearable headaches. She must keep them secret from the Bureau at the risk of her job while answering an internal call to protect women and children regardless of the cost. After two decades spent hunting serial killers, Agent Connelly thought she had seen it all. But delving deeper into the maze of clues dead-ends produces strange occurrences within her, awakening fragmented dreams and unsettling hallucinations. Are these clues leading her closer to the truth, or are they tricks of her overwrought emotions and exhausted mind? Are they buried secrets and elusive memories or is she losing her sanity? Engaged in a fierce psychological battle, she races against the ever-ticking clock to regain control over her body and mind. She must stop the killer--one way or another--before he claims another innocent family and she must add another item to her internal list of failures. She must stop him; her own survival and the lives of countless innocents hang in the balance. Why do these haunting crime scenes echo a clarion call in the deepest parts of her mind? Will catching the brutal serial killer silence the turmoil within her or will it only mark the start of a more intense, more personal battle?