Bonehead / Mo Hayder.

Alex Mullins knows she is one of the lucky ones. When a fatal coach crash at her school reunion killed several of her classmates, she was saved from a grisly fate. She is haunted by what she thinks she saw that night - a vision of a skeletal woman, known by the locals as the Bonehead - a woman who brings bad luck to all that see her. A mystery waiting to be solved. Now a police officer in Gloucestershire, Alex fights to overcome the past by helping other people. But when her path crosses with someone who was there that fateful night, her new life begins to unravel at the seams. What really happened the night of the crash? And what does she have to do for the petrifying Bonehead to finally leave her be?