After a failed uprising in Brittania, Sirona, a princess of the Iceni, and her lover, Taranis, are taken to Pompeii and sold as slaves. While Taranis is used to satisfy the demands of a rich Roman lady, Sirona is confined to the home of a lecherous senator until his stepson, General Lucius Flavius rescues her.

After the lovers are briefly united their situation takes a turn for the worst. Sirona finds herself in the clutches of the erotic cult of Dionysis and Taranis must fight for his life as a gladiator in the arena. Meanwhile, beneath Mount Vesuvius, there are forces gathering that even the power of the Romans cannot control.