At sixty-five, I believed there were certain kinds of pain a woman could no longer experience.

I had already buried my parents, watched friends grow old and disappear from my life, and sat beside hospital beds praying that the people I loved would recover. I had raised two children, welcomed four grandchildren, and spent forty-two years building a marriage that I believed would last until one of us drew our final breath.

I thought I understood my husband, Robert.

I knew how he took his coffee, which knee hurt when the weather changed, and why he always checked the front door twice before going to bed. I knew the sound of his footsteps on our wooden staircase and the particular way he cleared his throat whenever he wanted to disagree with me without starting an argument.

After forty-two years, I thought I knew the difference between his ordinary silences and the ones that meant something was wrong.