Book 5 Marriage: The Nightmare Years by Martha Byers Beall
Once a Catholic Series
Sara becomes the target of Owen's volatile nature, which grows worse with time. Owen's violent temper is the source of his erratic behavior that includes leaving illegible notes for Sara to find in the morning, moving pictures around on the walls, changing his will, all during his midnight meanderings. Three major illnesses are the products of his spiraling behavior. He targets Sara as his captive audience of one.