Five years after the Civil War, Captain Jefferson Kyle Kidd, a widowed, itinerant news reader, travels across Texas, bringing stories and news of the world to isolated communities. During his travels, Kidd comes across a horrific scene: a lynched black man and an overturned wagon. Investigating the wreckage, he finds a frightened young girl, Johanna. She was taken by the Kiowa tribe six years earlier and raised as one of their own. Coincidentally, the Union soldier tasked with returning her to her remaining family was the man lynched. Kidd reads her papers and learns she is to be transported to her surviving relatives hundreds of miles away.

With no authorities willing to take responsibility for Johanna, Kidd decides to deliver the girl himself. Johanna, resistant to a culture she does not remember, speaks little English, making communication between the two difficult. As they embark on their perilous journey through a harsh and unforgiving landscape, they face myriad dangers, from hostile terrain and natural disasters to the threat of bandits and lingering tensions from the recent war. Despite the barriers between them, the unlikely pair begins to forge a bond as they work together to overcome the obstacles on the road to Johanna's relatives, with Kidd serving as a reluctant protector and surrogate father figure to the lost girl.