The devil takes Maciste down to hell in an attempt to corrupt and ruin his morality.

In ancient Rome, tyrannical Emperor Caligula is assassinated through the machinations of Messalina. She then makes a conquest of Marcus, who forces the Senate to name her husband, Claudius, as emperor. Messalina's wicked ways continue when she falls in love with Ennio, a slave. Ennio is also loved by Egyptian princess Mirit, but he loves neither of them, preferring the company of Ela, a Greek slave.

"The Roman Banquet, the golden glories, the unrivaled luxuries, the wine, the dance, the song, the beautiful women, the sumptuous splendors that taxed a barbaric world for a night of feasting and revel-- Re-created for your entertainment in the most colossal drama produced", reads an ad in the Daily Argus of New York. Unione Cinematografica Italiana's lavish production of the oft-told tale stars Emil Jannings as Nero.