Episode 13: Unafraid of the Dark Episode 12: The World Set Free Episode 11: The Immortals Episode 10: The Electric Boy Episode 9: The Lost Worlds of Planet Earth Episode 8: Sisters of the Sun Episode 7: The Clean Room Episode 6: Deeper, Deeper, Deeper Still Episode 5: Hiding in the Light Episode 4: A Sky Full of Ghosts Episode 3: When Knowledge Conquered Fear Episode 2: Some of the Things that Molecules Do Episode 1: Standing Up in the Milky Way

Episode 13: Unafraid of the Dark Episode 12: The World Set Free Episode 11: The Immortals Episode 10: The Electric Boy Episode 9: The Lost Worlds of Planet Earth Episode 8: Sisters of the Sun Episode 7: The Clean Room Episode 6: Deeper, Deeper, Deeper Still Episode 5: Hiding in the Light Episode 4: A Sky Full of Ghosts Episode 3: When Knowledge Conquered Fear Episode 2: Some of the Things that Molecules Do Episode 1: Standing Up in the Milky Way

Episode 13: Unafraid of the Dark Episode 12: The World Set Free Episode 11: The Immortals Episode 10: The Electric Boy Episode 9: The Lost Worlds of Planet Earth Episode 8: Sisters of the Sun Episode 7: The Clean Room Episode 6: Deeper, Deeper, Deeper Still Episode 5: Hiding in the Light Episode 4: A Sky Full of Ghosts Episode 3: When Knowledge Conquered Fear Episode 2: Some of the Things that Molecules Do Episode 1: Standing Up in the Milky Way