Cefalonia tells the real story about what happened in September 1943 on the Greek island of Kefalonia (Cefalonia in Italian), when the 12,000 men in the Italian 33rd Acqui Infantry Division, following Italy's surrender to the Allied, refused to put themselves under German command and also refused to surrender their weapons. The local German force, supported by Stuka dive-bombers and additional troops, attacked the Italians and after several days of combat the Italians surrendered, having lost 1,300 men. As punishment, the German High Command ordered that all surviving Italians should be executed. Some 5,000 were executed during a week of killings. A handful were rescued by locals and the Greek guerrilla, while the rest were shipped off as prisoners, whereof 3,000 drowned when their ships hit mines. The film "Captain Corelli's Mandolin" is based on a novel about the Italian occupation of Cefalonia, but the massacre was much toned down in the Hollywood version.

Anna, a French journalist at the peak of her career, drops everything to pursue a small story. A mad and creative theater figure who died in the 1980s ignites in her passions and dormant doubts. She finds herself in a town in the Marche region, where her research on Roberto Cimetta begins. That carefree and rootless artist, perpetually traveling to European festivals, and his story captivate Anna so deeply that she imagines scenes, relives situations and impressions, trying to sort out her past.