Imagine rural Massachusetts of the 1690s. It's dark and dangerous. A handful of industrious Puritans try to eke out an existence in small towns and on isolated farms, surrounded by woods. When the work isn't physically exhausting, it's soul-crushingly boring. The only distraction is Sunday services, which include the constant threat of going to hell.Out of the darkness emerges an accusation, from neighbor against neighbor. The devil himself is afoot and urging his handmaids — the witches — to strike against their own community. Is it any wonder such a scenario would capture the hearts and minds of a stressed and isolated community? Alas, it wasn't a harmless diversion. The Salem witch trials instead led to the deaths by hanging of 19 innocent men and women charged with witchcraft. This strange spasm of injustice lasted from roughly June to September of 1692. Historian Stacy Schiff's latest book, The Witches, documents what is known about the victims, the accusers, the judges, the jailers, the witnesses and the entire community. Schiff's strength as a historian is that she sees people who lived centuries ago as not so different from ourselves, and she has a continuing fascination with the role of women. (Her previous book was a luminous biography of the ancient Egyptian queen Cleopatra.) In The Witches, Schiff brings a particular perceptiveness to the potential motivations and mind-sets of all the parties involved, but especially to the accusers. Young girls were the chief witnesses to the alleged witchcraft; they claimed to feel bodily torments and see demonic visions, including Lucifer himself, who supposedly offered enticements in return for the witches' deeds. "From those things the devil promised we can glimpse what the seventeenth-century girl dreamed of," Schiff writes. "Splendid finery, travel abroad, fashion books, leisure, gold, a husband to help with the housework. Her longings differed little from those of any other orphaned semi-adolescent farm girl stalled in a bleak, storm-prone landscape."But it was the men of Massachusetts who were ultimately in charge and who decided guilt or innocence. At the heart of The Witches is the contradictory preacher Cotton Mather. Mather advised the judges, documented court proceedings, issued his own advice on spectral evidence and ultimately defended the trials as valid processes. Mather was well-educated: Later, he would advocate for the scientifically sound process of inoculations as a means of warding off disease. Schiff calls him brilliant, prolific, tireless; the enigma of the book is why the best educated and most law-abiding men were so willing to go along with the illogical allegations of young girls. Religious zealotry, yes, but there's more to it than that, Schiff suggests. Perhaps there was score settling to be done between the accused and the accusers. Perhaps people just liked the drama. Perhaps we are all much less rational than we think ourselves to be.Gaps in the historical record make determining individual motivation very difficult indeed. Overall, though, The Witches is so detailed and comprehensive that it can be dull and hard to follow in stretches. The cast of characters at the front of the book contains a daunting 90-plus names. If you're looking for an exhaustive, blow-by-blow account of the trials, The Witches is excellent. But it may be too much information for those with a more casual interest.Eventually, the Salem witch trials seemed to burn themselves out. Within less than a year, it seems, the villagers of Salem lost interest in their quest to expunge the devil and his minions from their midst. "The shift came about less for any single reason than for twenty of them. Terror had worn out its welcome; the system and men's spirits were exhausted. The court had moved too aggressively and too expansively." It may be cold comfort to know that every fever eventually breaks. But it does seem to be the way that witch hunts, both old and new, ultimately play out. "It turns out to be eminently useful to have a disgrace in your past," Schiff concludes. "Salem endures not only as a metaphor but as a vaccine and a taunt. It glares at us when fear paralyzes reason, when we overreact or overcorrect, when we hunt down or deliver up the alien or seditious. It endures in its lessons and our language."Angie Drobnic Holan is the editor of PolitiFact. Follow @AngieHolan.