Wood travels through war-torn Afghanistan, crossing the Oxus River into Central Asia and the Silk Road city of Samarkand where, in a drunken brawl, Alexander killed the friend who had previously saved his life.

Beginning with the origins of the universe in the Big Bang, Sagan describes the formation of different types of galaxies and anomalies such as galactic collisions and quasars. The episodes moves further into ideas about the structure of the Universe, such as different dimensions (in the imaginary Flatland and four-dimensional hypercubes), an infinite vs. a finite universe, and the idea of an oscillating Universe (similar to that in Hindu cosmology). The search into other ideas such as dark matter and the multiverse is shown, using tools such as the Very Large Array in New Mexico. Cosmos Update shows new information about the odd, irregular surfaces of galaxies and the Milky Way perhaps being a barred spiral galaxy

Without words, Ron Fricke shows us the world, with an emphasis not on 'where,' but on 'what's there.' It begins with morning, natural landscapes and people at prayer: volcanoes, water falls, veldts, and forests; several hundred Balinese Hindu men perform kecak, the monkey chant. Indigenous peoples apply body paint; whole villages dance. The film moves to destruction of nature via logging, blasting, and strip mining. Images of poverty, rapid urban life, and factories give way to war, concentration camps, and mass graves. Ancient ruins come into view, and then a sacred river where pilgrims bathe and funeral pyres burn. Prayer and nature return. A monk rings a huge bell; stars wheel across the sky. (Click CC for places description)