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 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.

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.

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.

Huge asteroids have smashed into the earth, and turned it into an enveloped fire, uninhabitable to almost all life on the surface. The world will get hit again. It's just a matter of when. So, what should we do as a species? Should we just, like the dinosaurs, look up and die? The reasons the dinosaurs are extinct is they didn't have a space program. We do. We have the capability to perhaps escape the Earth.
Astronaut Chris Hadfield believes the only chance for human survival is to escape from Earth and build a space colony, but there are real barriers.

What makes us human is the squishy triple-pounder inside our heads. It lets us build skyscrapers, and lift a special few of us into space. We are the only species on this planet that can construct realities in our mind and then go actually build it. The story of how our mind evolved on this one strange rock is one of chance, coincidence and impossible odds.
This episode is an investigation into the mystery of the human brain and the chain of events that produced the anomaly of human intelligence.