The Haunted (Sarah Roberts Book Twelve)

Two decades ago, Sarah's sister Vivian was murdered. Vivian's consciousness has manifested itself in Sarah Roberts through Automatic Writing, but is now merging into Sarah's mind at a new level, causing Sarah to relive Vivian's brutal death almost daily.
Sarah moves into a cabin in northern California to be alone, to work things out. She visits a local psychologist to deal with what's happening to her, and researches the name Cole Lincoln, her old babysitter.

Lincoln was a police officer who lived next door to her. He abused her and threatened her life if she ever spoke of it. But he seems to have disappeared. Members of the police force where he used to work won't even acknowledge his name.
But Lincoln is alive and well. Since Sarah's name hit the national media with a cop killing in Canada and the priest killer case in Los Angeles, Cole has followed her exploits, watched her, and has waited for the day she would come after him.
That day has come.
While Sarah tries to deal with the haunting flashes of memory and images, Lincoln calls in a favor and gets her committed to a psychiatric hospital.
To shed the darkness that torments her, Sarah needs to set things right by making Lincoln pay for what he did. But Lincoln has other plans, and Sarah doesn't see him coming until it's too late.
Sarah has fought for her life before. In The Haunted, she also fights for her sanity.