Raised in a Pennsylvania Amish community, young mother Rachel Yoder has led a simple life within her close-knit family. Widowed three years ago, she has moved back in with her parents, attempting to raise her daughter, Katie, without further emotional upheaval. Meanwhile, four hours and a whole world away in New York City, Ellie Lawrence is laser-focused on a high-powered public relations career, with too little time for her family, her friends, or even her boyfriend.

Then one fateful day, these two very different women receive shocking news of a mistake made three decades earlier and long kept hidden: Shortly after their births, the two were accidentally switched in the hospital. Shaken to the core by this momentous news, Rachel and Ellie are plunged into an exploration of who they are and where they really belong. While Ellie is eager to learn more about her Amish family and their life in the countryside, Rachel cannot help but feel jealous as she watches the only mother she has ever known bonding so easily with her natural daughter. But Rachel also knows that her own biological family is out there, and with Katie at her side she heads for Manhattan, where she establishes a connection with the raucous, spirited Lawrences.

As Ellie and Rachel make their way through unfamiliar landscapes, they face life-altering challenges and grapple with a crucial question: Will their old conventions and desires give way to new customs and yearnings? With the Christmas holidays fast approaching, it takes the love of two families for Rachel and Ellie to discover their own paths to fulfillment and happiness.