Octavian takes a new bride, Livia, and then introduces her to his family in a startling way... by having her witness the punishment he metes out to Atia and Octavia, for secretly defying the social constraints established through the facade of Octavia's marriage to Mark Antony. The vengeful Gaia carries out her plan to poison Eirene, which produces most dire consequences for Pullo, and no one else is the wiser.
Meanwhile, Octavian, Antony, Maecenas, and their associates barely maintain their relationships of congenial contempt and hypocrisy, as everyone tries to figure out who has duped whom with the disappearance of the gold that was Herod's 'gift.'

With the defeat of the Egyptian fleet at Actium, Mark Antony and Cleopatra retreat to their palace and await their fate. Believing that Cleopatra has taken her life, Mark Antony decides follow her into the afterlife. She has other plans however and is quite prepared to negotiate with Octavian if there is any possibility her life and those of her children will be spared. Cleopatra asks Vorenus to take her son Caesarian to safety and Octavian sends Pullo after them. The old friends are soon together again.

Inconsolable at the death of Brutus at Philippi, Servilia makes her final bid to gain the ultimate vengeance against Atia. Meanwhile, Eirene and Gaia have a major falling-out, prompting Eirene to demand that Pullo properly chastise the slave. When he does, the dynamic between the two of them changes in a violent and unexpected fashion.
King Herod engages Mark Antony as a reluctant ally by offering a generous gift of 20,000 pounds of gold.

Vorenus and Pullo return to the Collegium in Rome with Vorenus' family, but some of the 'changes' that Pullo had warned him about regarding his two daughters Vorena both the Elder and Younger, as well as his wife's son, begin to manifest themselves into hostility and resentment.
But Vorenus is completely oblivious to this, and is too blissfully happy to return to the role of 'father'. Meanwhile, Octavian finally returns and manages to negotiate the Senate Consul's seat from a scheming Cicero.

Seven years have passed since Antony's departure from Rome, and the former commander, dissipated and debauched - held in thrall by the charms and sexual prowess of his new bride, Cleopatra, withholds precious shipments of grain from Rome, where people die in the streets from hunger.
Unable to incite a war with Antony and Egypt without committing political suicide, Octavian sends Atia and Octavia to Alexandria to mediate and reason with Antony; a strategy which proves predictably unsuccessful.

Caesar has been murdered, Mark Antony emerges from the Senate in shock, only to face Quintus Pompey and his thugs, who immediately follow him to try to kill him. Brutus returns home shaking after the murder. His mother is already plotting the return of the Roman Republic. Titus Pullo asks Eirene to marry him and she accepts. Erastes Fulmen kidnaps Lucius Vorenus' children and sister-in-law.
Mark Antony proposes an amnesty to the rest of the senate to keep the peace and allow the Republic to continue. Vorenus says goodbye to Niobe while Rome says goodbye to Caesar. Vorenus and Pullo track down Fulmen to a bath house, where he tells them he killed Vorenus' family.