THE START OF EVERYTHING. By Emily Winslow. Random House. 250 pages. $26.

The setting is the venerable town of Cambridge, England. A badly decomposed body of a young girl is found in the fens, a flooded low-lying marsh area. Identifying the body is a difficult task, and as the detectives search for clues, nothing is as it seems.

Why doesn’t she show up on missing person’s reports? Why isn’t her family looking for her? Is she perhaps from another country, an au pair?

Be prepared for mental gymnastics as author Emily Winslow tells the story through the eyes of the many diverse characters, delving into the dark side of the human psyche. This intriguing and cerebral book will keep an alert reader flipping back and forth through pages wondering what he or she missed.

Reviewer Frances Monaco is a writer in Charleston.

RIVER OF DARK DREAMS: Slavery and Empire in the Cotton Kingdom. By Walter Johnson. Harvard University Press. 420 pages. $35.

Just one of the appalling moments in this book comes with the story of Robert, who boarded a Mississippi River paddle wheeler in 1850, seated himself at the first table in the whites-only dining section and regaled other passengers with his gentlemanly ways and decorum.

He was at first thought Spanish, but as the New Orleans-to-Cincinnati trip plowed on, “the rumors, then the jokes — the doubts — intensified.”

By Memphis, “The captain then ‘told the boy that he would have to get off, and be confined until he could prove himself a white man and not a runaway. If he should prove a white man,’ ” the captain reportedly told Robert, he “would be extremely sorry for this course.”

That’s among the nicest things that happen to people of color in this morass.

Johnson’s book is an exhaustive academic work on the interplay of the Peculiar Institution and the Delta region’s flailing attempts at establishing its own empire. In its course, horror stories of race domination get twisted out of the historical record.

“River of Dark Dreams” is torturously riveting in places. But for the reader, Robert’s tale should be cautionary: It’s the “nice” one.

Reviewer Bo Petersen is a reporter for The Post and Courier.