We uncover the story of our relationship with the skies from our earliest ancestors, through to the birth of the science of astronomy. Our story begins with one of the earliest known creation myths - the Babylonian Enuma Elish. With spectacular CGI animation, we see the clash of the gods Marduk and Tiamat that the Babylonians believed gave birth to the earth and the sky. In this episode we visit the caves of El Castillo in Northern Spain. Deep inside the caves we see some of the earliest cave paintings in the world. Astronomer Phil Plait shows us how the skies could be used to navigate and tell the time, either by observing the phases of the moon, or by tracking the movements of the sun across the horizon. We look at Stonehenge and the Great Pyramid of Giza and see that, as our earliest civilisations developed, we built monuments that enabled us to observe the skies and worship them. We visit Ancient Greece, where the great storytellers Hesiod and Homer were populating the world with gods and monsters. That is until the first philosophers started to look at the world not in terms of individual events that showed the actions of living gods in the sky, but as phenomena that were all part of the patterns of the natural world. As philosophy and early science start to reshape the world from mythological to rational, we are on the cusp of a revolution that gave birth to modern science.