A game, an experiment, an original literary collaboration: the two most important authors of crime fiction in Italy join forces to offer us a story featuring Inspector Montalbano and Inspector Grazia Negro.

A strange murder that took place in Bologna brings them together. The victim was found with a plastic bag over their head, fully dressed, missing only one shoe; next to the body on the floor were three goldfish.

The case was taken on by Grazia Negro, who, upon discovering that the victim was from Vigàta, asked for help from her Sicilian colleague... But to what extent is Montalbano willing to help? Will he want to get involved and follow Grazia in a case that promises to be dangerous and against which their superiors have openly opposed in the investigation?

[Excerpt from the text on the back cover of the edition]