A story from a time when mystery made all the difference and where the most subtle sense of observation reigns supreme. It all begins with the death of the Swimmer, discovered at the edge of the cliff. But to this day, it is not known who fired the fatal shot, despite a thorough investigation by the Judicial Police, with special attention given to three girls—two sisters and a friend—who are there on vacation. But the doubt remains, and the inspector who conducted the investigation wonders, because the three seemingly naive teenagers leave the inspector with the conviction that, between their statements and their father's assertive maturity, it will be difficult to prove what his instinct tells him.