Tell No One
Harlan Coben

Everyone tells him it's time to move on, to forget the past once and for all. But for David Beck, there can be no closure. A message has appeared on his computer, a phrase only he and his dead wife know. Suddenly Beck is taunted with the impossible- that somewhere, somehow, Elizabeth is alive.
Beck has been warned to tell no one. And he doesn't. Instead, he runs from the people he trusts the most, plunging headlong into a search for the shadowy figure whose messages hold out a desperate hope.
But already Beck is being hunted down. He's headed straight into the heart of a dark and deadly secret- and someone intends to stop him before he gets there.