Set in Nauvoo, Illinois, she tells the story of a single family, a woman and her Mormon husband, loosely based on her in-laws' family history from the period and augmented by on-site research. The novel preceded the first scholarly treatment of Nauvoo by three years.
As an outsider, Sorensen's protagonist is puzzled by the city's mysteries. Gradually, however, she discovers that a neighbor's obsession with the LDS prophet is due to her polygamous marriage to him. Even so, Mercy Baker cannot foresee the complications that her own baptism will bring.