A game, an experiment, an original literary collaboration: the two most important crime fiction writers of contemporary Italy join forces and offer us a story featuring Inspector Montalbano and Inspector Grazia Negro, the main characters in their novels.

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

The case was taken on by Grazia Negro, who, upon discovering that the victim was from Vigata, sought help from her Sicilian colleague... But to what extent is Montalbano willing to help? Will he want to join the game and follow Grazia in a case that promises to be dangerous and openly opposed by their superiors?

A jam session between two ingenious writers who entertain each other by mutually influencing each other's style and imagination, a book not to be missed by anyone who loves crime fiction.