Told through their diary entries, Inherited Sins is the story of Johnnie Marie Martin, a young woman living on an isolated farm in 1940s west Texas, and Reverend Dan Fletcher, the pastor of the local church. Watching his beautiful wife slip farther and farther away from him after the death of their son, Reverend Fletcher comes to rely on his friendship with Johnnie Marie to battle through his own grief. As he falls in love with her, she reveals her dark past, the abusive and incestuous relationship she had with her father, and the desperate measures she took to protect her own daughter, Willa Mae. Old family secrets test the strength of love as one generation passes the burden of its sins onto the next.