Ebershoff intersperses two parallel tales in this book about polygamy among the Mormon community. The first is that of Ann Eliza Brigham, supposed 19th wife, but probably number 50+ of Brigham Young. After much resistance, Ann reluctantly became his wife in order to protect her parents and brother from hardship. Ann went on to escape, and to take her anti-polygamy story on the road. Ann is a true historical figure.

The second story is a murder mystery set in the present among a fundamentalist splinter group of still polygamist First Latter Day Saints. The murderer, Wife 19, was quickly identified with seemingly airtight evidence is behind bars, but she claims she is innocent, and banished gay son, who has come back to see her, begins to believe her. Of course no real investigation is taking place since the local police are all members of the sect. Jordan finds his mom a lawyer, and goes about investigating on his own, coming up with a startling conclusion that he likely won't be able to prove. A fascinating look at Mormon history, and polygamy.