In August 1969, medical student Lizzie Baker sets off on a trip to Woodstock with her boyfriend and two other couples. When their van breaks down outside of Morganton, North Carolina, the group decides to hike up nearby Brown Mountain while they wait for the repairs to be finished.

Lizzie's interest in nature prompts her to go on a walk by herself, hoping to get a glimpse of the legendary Brown Mountain Lights. When she unexpectedly encounters one, she naively reaches out to touch it and is thrown back in time to a place and lifestyle she comes to hate - the Antebellum South.

Lizzie is taken in by three sisters who are healers. With them, she is able to put her knowledge as a medical student to good use. She finds a trusted friend in Abbie, the youngest sister, and through a budding romance with the son of a plantation owner is drawn into the dangerous world of the Underground Railroad.

With a bloody and violent war looming on the horizon, at a time when women are looked upon as less than equal, Lizzie struggles to accept the differences that surround her every day in this new and challenging world. Wanting nothing more than to return home, she and Abbie continually search for the light Lizzie travelled through, hoping it will take her back to her time.

But if she finds it, will she decide to stay or go?