Glaucus, a centurion returning to his home in Pompeii after a spell in Palestine, arrives on the edge of town just in time to see Ione, the beautiful daughter of the city's Consul, lose control of her chariot. Glaucus saves Ione's life and then heads into town to see his father. On the way, Glaucus intervenes in defense of a thief named Antonius, who is being severely punished on orders given by Gallinus, a Praetorian Guard. On arriving at his father's house, Glaucus discovers that it has been looted and his father murdered by a band of ruthless hooded thieves who have been terrorizing the city, always leaving a cross painted on a wall as a calling card. Glaucus vows revenge against the killers.