Commissario Brunetti XV. On a luminous spring day in Venice, Brunetti and his assistant Vianello play truant from the Questura in order to help Vianello's friend Marco, arrested while protesting against chemical pollution of the Venetian lagoon. They secure his release, only to be faced by the fury of Marco's father-in-law, a cantankerous glass factory owner. The old man is seething with rage at his son-in-law and his daughter tells Brunetti that she fears her father will harm her husband. But it isn't Marco who's uncovered the guilty secrets of the glass factories - nor his body that is found dead in front of one of the furnaces that burn at 1400 degrees, day and night. The victim has left clues in a copy of Dante and Brunetti must descend into an inferno to discover who is burning the island and fouling the waters of the laguna. A man is dead - but will politics and expedience protect the killer from the law?