“Darkest Fear” by Harlan Coben

Edgar Award-winner Harlan Coben brings us his most astonishing—and deeply personal—novel yet. And it all begins when Myron Bolitar’s ex tells him he’s a father … of a dying thirteen-year-old boy.
Myron never saw it coming. A surprise visit from an ex-girlfriend is unsettling enough. But Emily Downing’s news brings him to his knees. Her son Jeremy is dying and needs a bone-marrow transplant—from a donor who has vanished without a trace. Then comes the real shocker: The boy is Myron’s son, conceived the night before her wedding to another man.
Staggered by the news, Myron plunges into a search for the missing donor. But finding him means cracking open a dark mystery that involves a broken family, a brutal kidnapping spree, and the FBI. Somewhere in the sordid mess is the donor who disappeared. And as doubts emerge about Jeremy’s true paternity, a child vanishes, igniting a chain reaction of heartbreaking truth and chilling revelation.