After a failed uprising in Britannia, 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 at the home of a lecherous senator until his step-son, General Lucius Flavius rescues her.
The lovers are briefly reunited but their situation takes a turn for the worse. 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.