What initially seems like an isolated case of religious fanaticism quickly takes a sinister turn when a second, identical doll is found in a trash bin. Shortly after, Montalbano begins receiving anonymous letters containing riddles that challenge him to a "treasure hunt". As the riddles grow more complex and a young woman is reported missing, Montalbano realizes he is being manipulated by a disturbed maniac who intends for the "treasure" at the end of the hunt to be a corpse.
Alberto Sironi, the long-time director of the series who defined its iconic visual style.
Based on the novel The Treasure Hunt by Andrea Camilleri .