Montalbano investigates the seemingly accidental killing of a fisherman aboard a Vigata fishing boat and uncovers far-reaching criminal activity in the process.
During the investigation, Fazio seems distracted and Montalbano soon discovers that the young policeman has become involved in protecting a local family from death threats during his spare time.
Meanwhile, as the wedding preparations continue, Livia's and Salvo's relationship looks like it might have run into trouble.