 In the town of Pompeii, 79AD, a few weeks before the volcanic eruption of Vesuvius, a Roman lady Hélène meets and falls in love with a young Greek man Lysias. He is betrothed to another woman who, to win him back, acquires a potion to make him love only her. The potion was prepared by the Egyptian priest, Arbax, who has a grudge against Lysias, and is not what it seems, it is intended to drive whoever takes it insane. Hélène s new slave is also in love with Lysias. She steals the potion and gives it to Lysias, who hurries away in a mad rage. When the slave girl confronts Arbax, she is killed by the evil priest, and Lysias is charged with her murder.