Professor Jim Al-Khalili continues his investigation of the atom by looking at radioactivity, the Atom Bomb and the Big Bang, and even why we are here and how we were made. He shows that, in the quest to understand the atom, the mystery of how the entire universe was created became revealed

The simple act of making an apple pie is extrapolated into the atoms and subatomic particles (electrons, protons, and neutrons) necessary. Many of the ingredients necessary are formed of chemical elements formed in the life and deaths of stars (such as our own Sun), resulting in massive red giants and supernovae or collapsing into white dwarfs, neutron stars, pulsars, and even black holes. These produce all sorts of phenomena, such as radioactivity, cosmic rays, and even the curving of spacetime by gravity. Cosmos Update mentions the supernova SN 1987A and neutrino astronomy.

Inside the heart of the atom, its nucleus houses energy. This hidden treasure was forged billions of years ago in distant stellar furnaces. The secret of starlight is nothing to fool with. It can bring a civilization to life and it can burn it to the ground.
Two atoms from different parts of the universe meet on a small planet. A deadly embrace between science and state altered the fate of the world and a gripping cautionary tale of others who grew used to living in the shadow of grave danger until it killed them all except one.

In the second episode, panic strikes the community as a full-blown catastrophe looms. Locals mobilize to confront the authorities and protest the nuclear power industry.
Twenty-eight hours after the accident began, the lieutenant governor appeared at a news briefing to say that the plant's owner had assured the state that 'everything is under control'. Later that day, Scranton changed his statement, saying that the situation was 'more complex than the company first led us to believe'. There were conflicting statements about radioactivity releases. Schools were closed and residents were urged to stay indoors. Farmers were told to keep their animals under cover and on stored feed.