Judgment of the Grave (Sweeney St. George Mysteries)

As gravestone expert Sweeney St. George tours burial sites of the Civil War, she stops to watch a battlefield reenactment in Massachusetts. There, she meets Pres Whiting, a boy whose family is in the gravestone business. When Pres discovers a dead man in a Revolutionary War-era British soldier's uniform, Sweeney and Cambridge homicide detective Tim Quinn jump on the case.
While they search for clues regarding the dead body, Sweeney and Quinn investigate other strange events. While Sweeney looks into the 1775 disappearance of militiaman, Quinn looks into a current missing persons case with alarming ties to the past. As they try to uncover how their own investigations are related to the body found in the woods, Sweeney and Quinn get a little too close for comfort -- to each other and to murder.