Members of the Dante Club, a group of poets translating The Divine Comedy from Italian into English, notice the parallels between the murders and the punishments detailed in Dante's Inferno. The club, including Henry Wadsworth Longfellow, Oliver Wendell Holmes, Sr., and James Russell Lowell, sets out to solve the murders, fearing that the truth will ruin Dante's burgeoning reputation in America, thus making their translation a failure. Then, Phineas Jennison, both a wealthy contributor to the Harvard Corporation and friend to the translators (a "schismatic"), is sliced open exactly down the middle—all killed in extreme fashion and undeniable resemblance to the punishments of people in Dante's Inferno.
Eventually, the murderer is discovered to be a former Civil War Soldier Dan Teal, a man who worked at Ticknor and Fields. Driven partly mad by the trauma of his war experiences, Teal hears Dante Club member George Washington Greene giving sermons on Dante, and becomes convinced that Dante alone understood the need for perfect justice in the world. With protecting Dante as his sole motivation, Teal takes it upon himself to release Hell's punishments as indicated by Dante, in order to purify the city. Teal finds each of his victims when learning of their involvement in the stopping of the