In the wake of Julius Caesar's triumph in Gaul, two soldiers are sent to retrieve the army's golden eagle standard while Caesar's former ally Pompey Magnus begins to plot against his old friend.
Vorenus and Pullo return to Rome in the company of Marc Antony and Octavian, where Vorenus is reunited with his wife. Pompey prepares an ultimatum that will strip Caesar of his power.
As Caesar advances on Rome, Pompey makes a curious tactical decision by deserting the city along with the senate.
Caesar institutes martial law in order to quell the chaos and to consolidate his sway over Rome while Vorenus makes an effort to start a new life as a merchant.
Caesar mulls over a counteroffer from Pompey while Vorenus must reconsider his financial options after his shipment of slaves from Gaul all die of sickness and Atia plots to come between Caesar and Servilia.
It is Caesar's turn to become the hunted one after pursuing Pompey to Greece, where Pompey brings in legions from the East and Caesar finds himself outnumbered. Meanwhile, Antony does his best to run Rome in Caesar's absence and is presented with an offer to betray his friend and Pullo continues his tutelage of Octavian by taking him to a brothel.
While Vorenus and Pullo struggle to survive after being marooned in the Adriatic Sea, Pompey makes his move by attacking Caesar's weaker forces.
Caesar's pursuit of Pompey takes him to Egypt where he meets with the boy-king Ptolemy and learns of Pompey's assasination, news that infuriates him. In the meantime, Vorenus and Pullo are sent to free Ptolemy's incarcerated sister, Cleopatra.
Caesar comes back to his home. Vorenus and Pullo face off against a local.
While Caesar is anointed emperor, Vorenus and Pullo begin planning their futures as civilians.
With few options, Pullo turns to Rome's underworld while Vorenus finds himself rewarded for his allegiance and Brutus is pressured to act against Caesar.
Pullo and Vorenus are surprised when they are rewarded for their exploits in the arena and Caesar's decision to overhaul the Senate raises tensions even higher while Niobe becomes a pawn in Servilia's plan for revenge.