As they prepare their counterattack against Caesar, Pompey's Republicans begin to squabble over both the anticipated spoils and the method of finishing Caesar off. Badly outnumbered, Caesar and Antony make their stand at Pharsalus. As they try to reach Caesar in Greece, the shipwrecked Vorenus and Pullo confront an unexpected dilemma.
Back in Rome, Atia again sends Octavia to beg protection from Servilia, who complies readily to encourage her growing friendship with Octavia. Niobe's sister Lyde comes back to see her and comforts her over Vorenus's disappearance.

In Egypt, Caesar rebukes the advisers of the boy king, Ptolemy XIII, for their presumption in eliminating Pompey and demands the man who killed him. Caesar decides to intervene in the dispute between Ptolemy and his sister-wife, Cleopatra, to ensure both Rome's grain supply and his own access to Egypt's treasure.
Antony, in an unusual show of prudence, advises against this with only half a legion in Alexandria and Cato and Scipio still at large in Africa. In Rome, Brutus gets a chilly reception from Servilia when he returns home from Greece.

The defeated Cato and Scipio fall back on the African city of Utica after the Battle of Thapsus where they decide to end it all. Caesar, after two years of fighting in Greece and Egypt, returns to Rome and receives a hero's welcome.
Meanwhile, Servilia's cold rage against the Julii clan makes Brutus's submission to Caesar even more painful. Octavian returns home from military school and Caesar, impressed with his nephew's incisive political acumen, appoints him a pontiff despite his youth.

The price of Caesar's mercy: Cicero nominates Caesar to an unprecedented ten-year dictatorship and Brutus speaks in support of the motion. With martial authority and Niobe at his side, Vorenus campaigns for magistrate under Posca's advice, but is shocked to learn from Posca that Caesar has already fixed the election in Vorenus's favor.
Meanwhile, Atia continues her humiliation of Servilia while denying any involvement in her assault.

Vorenus' defense of Caesar lands him in an unexpected position of power within Rome. Meanwhile, Servilia hurls the final obstacles in her ambitious and complex revenge plan against Caesar and Atia.

Lucius Vorenus, the power-hungry 'Son of Hades', controls the Aventine but practices a pointless, beastly reign of terror, coming down hard on gang captains for futilities, and nearly ruins his friendship with Pullo, whose efforts to calm things down are mistaken for disrespect and disobedience, even starts a fight once he learns the truth about Niobe; Pullio leaves Rome disgusted.
After Atia convinces Marc Antony the governorship of ghastly Macedonia after his consulate would not only be unpleasant but leave him exposed to his dangerous enemies.