As a foreign correspondent, Alex Callahan has travelled to some of the most dangerous corners of the globe. But he has never known the visceral terror that seizes him when, on a perfect summer afternoon, his six-year-old twins vanish without trace. Then the phone call comes: chilling silence, slow, steady breathing, then a familiar, plaintive voice -"Daddy ?"- sets in motion a waking nightmare. Knowing that time is running out and leads are being exhausted, Alex vows to use his own investigative skills to rescue his children from the shadowy figure dubbed "The Piper". Before long, he finds himself closing in on a monster with a mission -a twisted soul hell-bent on fulfilling a dark dream, a fiend with a terrifying true calling...