Taranis is sold as a slave to a rich Roman lady, who wants him for her bed, and Sirona is taken to the home of a lecherous senator, but he is only charged with her care until his stepson, General Lucius Flavius, returns home. Flavius rescues her from the corrupt household, and takes her to his villa outside the city. There, Sirona soon succumbs to his charms. However, with the help of the general's sister, Taranis and Sirona are briefly united, but the senator discovers their deception, and the situation takes a turn for the worst. Sirona must escape from the clutches of the followers of the erotic cult of the Dionysis, while 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.