Dead Write (2007)

After driving husband Martin to infidelity and catching him with another, mentally unstable author Jade returns to her New Zealand home. The plan is to write a book based on the town's history, helped by the local school teacher and her college thesis protégée, and visit her father Christopher. As her editor later explains, her suspicions concerning ever more locals stem from a pathological mental condition. However, more then just paranoia comes with the horse riding incident which killed her ma, an obsessive guilt matter for her and Christopher.