The Breakdown by B.A. Paris

A woman in a rush to get home late one night takes a remote path and sees a woman in her car by the side of the road. She doesn't stop and the next day learns that the woman was murdered. Distraught over not stopping to help, she begins to misplace things, forget important dates and begins to fear the incessant phone calls and little things that are off at home. Is someone stalking her because of what she might know or what her husband fears is dementia. Suspenseful but it felt a bit predictable. Still, another solid thriller that will keep you reading until the end and then checking the locks.