What if you had the power to amend choices you made in the past? Would you do it even if it changed everything?

Mercy Land has made some unexpected choices for a young woman in the 1930s. The sheltered daughter of a traveling preacher, she chooses to leave her rural community to move to nearby Bay City on the warm, gulf-waters of southern Alabama. There she finds a job at the local paper and spends seven years making herself indispensible to old Doc Philips, the publisher and editor. Then she gets a frantic call at dawn --- it’s the biggest news story of her life, and she can’t print a word of it.

Doc has come into possession of a curious book that maps the lives of everyone in Bay City --- decisions they’ve made in the past, and how those choices affect the future. Mercy and Doc are consumed by the mystery locked between the pages --- Doc because he hopes to right a very old wrong, and Mercy because she wants to fulfill the book’s strange purpose. But when a mystery from Mercy’s past arrives by train, she begins to understand that she will have to make choices that will deeply affect everyone she loves --- forever.