Louise Till, mother of two, has inherited her father's hardware store after her parents' unexpected deaths. She begins to cut copies of her customers' keys for herself, each one a talisman against grief and the terrible guilt she feels at not having realized that her parents were desperately unhappy.

Louise could use the keys, but she doesn't. Not until her life is overturned, again, when her marriage falls apart. Lou gives in to temptation, letting herself into Euphemia Rosenbaum's home. What follows is a tale of blackmail, break-ins, an unsolved mystery, and more...