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 fourth episode sees host Neil deGrasse Tyson exploring our eternal quest to end hunger and honoring Nikolai Ivanovic Vavilov, pioneer of modern plant breeding, who risked his life for a discovery that would change the history of science. Vavilov's story is marked by both the tenacity and creativity and is particularly tragic. Interwoven into Vavilov's somber narrative are warnings and treatments of science and its ethical implications, especially when science itself comes under attack from political forces.

Washington, D.C. is in many ways a city of extremes. Starland Vocal Band, Marvin Gaye, Duke Ellington, Nils Lofgren, Chuck Brown, Henry Rollins, Fugazi and Trouble Funk all hail from D.C. In the early '70s, the music style go-go originated here, and has remained a local craze ever since. Dave Grohl sits down with Trouble Funk's Big Tony Fisher to talk about go-go, and explores its origins with Chuck Brown, the genre's undisputed godfather.
He also chats with Don Zientara, owner of Inner Ear Studios, which the Virginia-raised Grohl says 'produced the entire soundtrack of my youth,' as well as with members of the harDCore band Bad Brains and Ian MacKaye of Teen Idles, Minor Threat and Fugazi, who all recorded at Inner Ear over the decades. The song 'The Feast and the Famine' is recorded during this episode.

The story of how the secret of life has been examined through the prism of the most complex organism known - the human body. It begins with attempts to save the lives of gladiators in Ancient Rome, unfolds with the macabre work and near-perfect drawings of Leonardo in the Renaissance, through the idea of the 'life force' of electricity, to the microscopic world of the cell. It reveals how a moral crisis unleashed by work on the nuclear bomb helped trigger a great breakthrough in biology - understanding the structure and workings of DNA.

When the followers of the Indian so-called 'guru of sex', Bhagwan Shree Rajneesh, start to build a utopian city in the Oregon desert, a massive conflict with local ranchers ensues; producing the first bioterror attack in US history, the largest case of illegal wiretapping, and the world's biggest collection of Rolls-Royce automobiles.
In the first episode, under the watchful eye of his secretary, Ma Anand Sheela, spiritual leader 'Osho' moves his ashram from India to Oregon in 1981.

Ma Anand Sheela emerges as a provocative spokeswoman. The Rajneesh control Antelope city council and they establish a police force in the city. Bhagwan tells Sheela it is time to control Wasco County. As Election Day approaches, the Rajneeshees recruit thousands of homeless people to fortify their ranks.