When Nic, a slave in the mines outside of Rome, is forced to enter a sealed cavern containing lost treasures of Julius Caesar, he finds himself in possession of an ancient amulet filled with magic once reserved for the Gods, and becomes the center of a conspiracy to overthrow the emperor and destroy Rome.

Nicolas Calva has Caesar's magic bulla, the Malice of Mars, and he has hidden the dangerous Jupiter Stone, but he still has to find a way to defeat The Mistress, a dragon who contains the soul of the vestalis Atroxia, and who hates Rome, and save his mother and friends, and maybe even the Empire itself--and he is troubled by his sneaking sympathy for Atroxia, who was unjustly condemned.

Suspecting their friend Jonathan is alive, Flavia, Nubia, and Lupus go to Rome for the Colosseum Games, facing wild beasts, criminals, conspirators, and gladiators, and where Nubia is called upon to make a terrible choice.

Flavia and Nubia follow Jonathan to Rome and into the Golden House built by the emperor Nero, where a dangerous assassin lurks.

Flavia and her friends go to Rome to celebrate the Festival of Jupiter at Senator Cornix's town house, where they befriend the young charioteer, Scopas, and quickly find themselves embroiled in a campaign to sabotage one of the rival racing factions.

Flavia and her friends pursue tutor Aristo from Corinth to Athens when he escapes after being accused of committing a brutal attack on Flavia's father.