Life on Earth has spent four billion years responding to the planet's own violent history, and this episode of the BBC's Earth Story series traces that link directly. Presenter Aubrey Manning follows the evidence that plate tectonics did more than reshape coastlines: as continents split and collided, they created and destroyed the isolated habitats that pushed evolution toward new species. Volcanic eruptions, meteorite impacts, and sharp climate shifts appear as the flip side of that story, wiping out huge swathes of life in mass extinctions while clearing space for survivors to diversify. Live-action footage shot at active volcano craters and on the ocean floor is combined with computer animation to show processes no camera could otherwise capture, including continents drifting across geological time. The series took three years to film worldwide, and this installment uses that reach to argue that Earth's geology and its biology have never really been separate stories, just two accounts of the same four-billion-year event.