Every Hidden Thing

In the Acknowledgements section, the author explains that his story was inspired, in part, by rivalry of two American paleontologists in the late-19th century. So expect both a primer on paleontology (the names of different bones, how to tell the difference between bone and rock in the field, how to set up an excavation site. etc....) and on life in the Badlands post-Civil War. Readers board the Transcontinental Railroad and experience a rough-and-tumble Western town complete with gambling halls and bordellos. The story also briefly touches upon the plight of the Sioux and Lakota people at that time and talks about Sioux funeral practices. Also explored: how hard it was to be a woman scientist in that era.

It's clear that Samuel and Rachel don't have the best role models in their fathers. Throughout the book they discover harsh realities about them -- Sam's father's impulsiveness and showiness, Rachel's father's snobbishness, sneakiness, and lack of respect for Native Americans -- and make conscious decisions not to be like them. Sam's still impulsive and Rachel's standoffish at times, but they work hard to find themselves and make their own way apart from their fathers.

A few scenes of sex between older teens after they marry, with some descriptions of getting naked, pain the first time, and getting a "rubber" in town so the wife doesn't get pregnant. Talk of erections and a few bawdy jokes. Plus one very minor character works in a bordello, another walks into a bordello by accident, and talk about a bordello upstairs from a rowdy bar.