Rejected by Vorenus and Eirene and racked by guilt for the killing of Eirene's fiancé out of a jealous rage, Pullo has sunk to working as an assassin for the gangster Erastes. When Pullo gets arrested for killing one of Caesar's popular opponents, he condemns himself by refusing to name who hired him, despite Octavian's attempts to defend him.
Meanwhile, Vorenus finds his new official duties as magistrate tedious, especially when he gets caught between Caesar and the demands made by veterans' spokesman Mascias.

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.

Even though his wife and children are avenged by the Erastes killing, Lucius Vorenus keeps mourning for over a month till Pullo gets Marc Antony who scolds him for Caesar's death and the continuing bloody Aventine gang riots that have resulted in the gangs wanting to fill the void left by Erastes sudden demise.
Octavian is loosing patience with Mark Antony for payment of Caesar's inheritance. Meanwhile, Queen Cleopatra of Egypt arrives in Rome to pay her respects to Caesar and she also negotiates with Antony's military protection for her Pharaonic throne.

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.

Having learned that Vorenus' children are alive, Pullo sets off to find him in Gaul where he is again a serving soldier in Mark Antony's army. He had hoped to arrive before Octavian and Antony's armies meet in battle. Too late however, he is forced to find what is left of Antony's army in the mountains. He finds Vorenus alive and well, if somewhat battle worn, and they set off to find the children.
The victorious Octavian plans his return to Rome. In Western Turkey, Brutus and Cassius amass their own army, now 19 Legions strong.

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.