Brian Cox spends this episode of Wonders of the Universe on the idea of destiny, tracing how humans have tried to read their fate into the sky and the calendar. He walks the ancient sites of Peru, where lines and markers cut into the landscape once tracked solstices and seasons for civilizations trying to fix their place in time. From there the film widens the lens: the sun's slow arc around the Milky Way takes roughly 230 million years to complete, a cycle so long it dwarfs every human calendar ever built. Cox uses the life cycle of stars, from formation in gas clouds to collapse and death, to show that the same physical laws governing a person's lifespan also govern galaxies. Location footage of deserts and ruins alternates with visualizations of stellar processes, and Cox narrates throughout, connecting each piece of physics back to the human question of whether the future is fixed or open. The episode treats destiny as a scientific problem as much as a philosophical one.