In 1851 Irish Famine survivor, Meg O'Connor, buys passage to America for her younger sister, Kathleen, and arranges employment for her as a maid. Kathleen's feisty spirit soon puts her at odds with her employers, the bigoted and predatory Pratts. Driven from their home, Kathleen ends up on a wild adventure taking her to places she could never have imagined.

As a domestic servant in the Worcester, Massachusetts home of the kindly Claprood family, Meg enjoys a life beyond her wildest imaginings. Yet she must keep her marriage to Rory Quinn a secret. Rory, still in Ireland, eagerly awaits the day he will join her. But as the only jobs open to Irish men pay poorly, Rory's imminent arrival threatens to plunge her back into dire poverty.

On the eve of the Civil War, while America is being rent asunder by the fight over slavery, Irish Catholics wage their own war with the growing anti-immigrant Know Nothing party. Through grave doubts, dangers, and turmoil, Meg and Kathleen must rely on their faith and the resilient bonds of sisterhood to survive and claim their destinies in a new and often hostile land.