Deputy Marshall Archie Lean is the primary investigator but this case is like nothing he's ever seen. Dr. Virgil Steig asks one of his former students for help. Perceval Grey is a brilliant criminalist. He's part Abenaki Indian and a former Pinkerton agent.
There are a number of uncanny similarities in this plot to Matthew Pearl's recent novel, "The Technologists."
Where this novel takes place in Portland, Maine, in 1892, Pearl's mystery occurs in 1868 in Boston. Perceval Grey uses modern investigatory methods and possesses a unique understanding of people and possible motives. This is similar to Marcus Mansfield in Pearl's novel. Mansfield is about to graduate from Massachusetts Institute of Technology and is scientific in his work.
Both men are ahead of their time in the analytical approach to investigating and the use of modern scientific methods. In addition, there is a bright woman helping with the investigation in both novels and both novels bring in witchcraft as having something to do with the story.
In "The Truth of All Things, the author demonstrates his talent for describing his characters and making them believable and worthy of our interest. However it is more like learning about the characters from newspaper accounts so we're not drawn to particularly 'like' the characters.
The exception to this is Archie Lean. We become interested in him not only for his stick to it, investigation but we learn that he is expecting a child. I was drawn to his relationship with his wife as the new baby's birth nears. Their concern for their crowded home and the economics of an expanding family are subjects that could be taken out of today's newspapers.
Helen Prescott assists the investigators considerably. She is a historian, knowledgeable in the history of the Salem witch trials. She is a modern woman of her day and doesn't let the other characters tell her what to do.
It is the connection to the Salem witch history that sets this novel apart. We are given information on the names of those tried and why they were accused of being witches. This is tied in nicely with the crimes of 1892.
The action evolves slowly, sometimes exasperatingly so as the investigators sift through one cue after another. However it all comes together nicely with a suspenseful conclusion.