Pietro, a pediatrician, widowed for years, lives for his profession in the bright San Pietro Island. Someday his daughter Elena, a young policewoman, reappears in his life. After fifteen years of absence, the woman stays in Carloforte to investigate the collapse of a tuna factory that killed few young and doesn’t seem to be an accident. Who would kill a group of eighteen years old kids? By her side during investigation, Alessandro, the first love -and also vice police commissioner of the island- she had to abandon for a unmentionable secret… Because she is the unknown mother of Caterina, a girl unaware of the true identity of her mother and who lived in Carloforte for fifteen years with a friend of Sereni’s family. And now Caterina seems to be guilty of the explosion and about to do something desperate