A Swedish film troupe arrives to shoot a period drama in Vigata. Augello immediately takes a shine to the production's female lead. When Montalbano intervenes in a case of bullying at a local school, a town resident asks the inspector to unearth the story behind a collection of mysterious home movies found in his dead father's attic.

It's high summer in Vigata and the murdered body of a young woman, Agata Cosentino, is found in the municipal archives where she worked. But the building was supposed to be closed for the holidays, so what was Agata doing there? Meanwhile, Adelina's wayward son Pasquale is engaged in a stand-off with a local security guard, Romildo Bufardeci, a former classmate from elementary school who is now intent on putting a stop to Pasquale’s petty criminality. As chief law enforcer, Montalbano must investigate any wrongdoings while also navigating the rivalry between the two men.