This episode explores the nature of the greenhouse effect (discovered by Joseph Fourier and Svante Arrhenius), and the evidence demonstrating the existence of global warming from humanity's influence. Tyson begins by describing the long-term history of the planet Venus; based on readings from the Venera series of probes to the planet, the planet had once had an ocean and an atmosphere, but due to the release of carbon dioxide from volcanic eruptions, the runaway greenhouse effect on Venus caused the surface temperatures to increase and boiled away the oceans. Tyson then notes the delicate nature of the amount of carbon dioxide in the atmosphere can influence Earth's climate due to the greenhouse effect, and that levels of carbon dioxide have been increasing since the start of the 20th century. Evidence has shown this to be from mankind's consumption of oil, coal, and gas instead of from volcanic eruptions due to the isotopic signature of the carbon dioxide. The increase in carbon dioxide has led to an increase in temperatures, in turn leading to positive feedback loops of the melting polar ice caps and dethawing of the permafrost to increase carbon dioxide levels. Tyson then notes that humans have discovered means of harvesting solar power, such as Augustin Mouchot's solar-driven motor in the 19th century, and Frank Shuman's solar-based steam generator in the 1910's. Tyson points out that in both cases, the economics and ease of using cheap coal and oil caused these inventions to be overlooked at the time. Today, solar and wind-power systems would be able to collect enough solar energy from the sun easily. Tyson then compares the motivation for switching to these cleaner forms of energy to the efforts of the Space race and emphasizes that it is not too late for humanity to correct its course.

Born in Groot-Zundert, The Netherlands, Van Gogh spent his early life as an art dealer, teacher and preacher in England, Holland and Belgium. His period as an artist began in 1881 when he chose to study art in Brussels, starting with watercolours and moving quickly on to oils. The French countryside was a major influence on his life and his early work was dominated by sombre, earthy colours depicting peasant workers, the most famous of which is The Potato Eaters, 1885. It was during Van Gogh's studies in Paris (1886-8) that he developed the individual style of brushwork and use of colour that made his name. In 1888 he moved to Arles where the Provençal landscape provided his best-known subject matter. However, it also marked the start of his mental crisis following an argument with his contemporary Paul Gauguin. Van Gogh was committed to a mental asylum in 1889 where he continued to paint, but he committed suicide in 1890.

The Earth was formed by a series of cosmic cataclysms including the most powerful blast in the Universe. Yet amid the turmoil our world was born. Could the same chain of events have created other earths elsewhere, inhabited by creatures like us?