Dead Write (2007)

Following her husband Martin's affair with a troubled author, Jade returns to her native New Zealand. She intends to write a book about the town's history, working with the local schoolteacher and her student, while also visiting her father, Christopher. As her editor later reveals, Jade's increasing distrust of the townspeople is linked to a serious mental illness. But beyond paranoia, the anniversary of a horse riding accident that killed her mother—a source of intense guilt for both Jade and Christopher—adds further complications.