Based on Edward Bulwer-Lytton's 1834 novel of the same name, the film - one of two different adaptations of the same book in Italy that year - is set during the final days leading up to the Mount Vesuvius eruption in Pompeii in 79 AD.
Glaucus buys the blind slave Nydia who is mishandled by her owner.
Arbax' disciple Apoecides threatens to reveal publicly his wrongdoings.
Nydia manages to escape and tells Glaucus' friend Claudius what happened.
The Vesuvius starts erupting and a widespread panic ensues.