Semiramis, a powerful and beautiful Assyrian queen, oversees the construction of the luxurious city of Babylon. She falls in love with Kir, a fallen prince turned into a slave who corresponds to her love. But a palace conspiracy will make the two lovers separate and confront each other.
The film shows how Italy's historic national hero Giuseppe Garibaldi (embodied by Renzo Ricci) leads a military campaign known as Expedition of the Thousand in 1860 and conquers Sicily and Naples. When the Bourbon monarchy has left Southern Italy, he supports Victor Emmanuel II of Italy who achieves a lasting unification under the aegis the House of Savoy. Roberto Rossellini has said he was prouder of this film than of any other film he ever made.
Claudia and Anna join Anna's lover, Sandro, on a boat trip to a remote volcanic island. When Anna goes missing, a search is launched. In the meantime, Sandro and Claudia become involved in a romance despite Anna's disappearance, though the relationship suffers from guilt and tension.
During a reception in a villa, wealthy banker Calandri is killed in the park with a gunshot. The gamekeeper Barra is immediately arrested, but he declares himself innocent. During the trial it turns out that the defendant had threatened the victim, guilty of courting his sister-in-law. But the deposition of a journalist present at the party soon leads to discover the existence of a dense network of equivocal relations between the victim, the guests and the servants. This judicial setting drama is allegedly the second Italian sound film after "The Song of Love", made using the RCA Photophone recording technique, and is also considered to be the first Italian detective film, a precursor to the later genre of Giallo films.
