A Brief Lunacy — Cynthia Thayer

An elderly couple is taken captive in a psychological thriller that “coils tighter and tighter until the tension is almost unbearable” (Tess Gerritsen).
 
Jessie and Carl have made a terrible mistake. When Jonah came to their cabin in the Maine woods, asking to use the phone, they should never have let him in. But he told them his campsite had been robbed and he was stranded with no money and no gear. Jessie took pity on him. She was thinking about her own missing schizophrenic daughter, and hoping she was receiving the same kindness -- wherever she was.
 
They invite him in, share their dinner with him, and offer him a bed for the night. They soon discover that this stranger at their table knows all about them, all about their troubled daughter, and all about the secrets they haven't revealed to each other during forty years of marriage. By morning, they realize the young man has no intention of leaving . . .
 
“A sober, wrenching literary thriller . . . The dark suspense in this concentrated psychological character study makes for a genuine page-turner.” -- Publishers Weekly