Prince William, founder of the Earthshot Prize, is joined by Prize Council members Sir David Attenborough and Hindou Oumarou Ibrahim, an indigenous rights spokesperson from Chad, to explore the story of our wastefulness and how we might move to a waste-free world.They reveal the extent of our careless approach to producing waste, both non-biodegradable and biodegradable, and discover that we can solve the waste problem by reimagining our production lines as materials circles, ensuring that the waste from one process becomes the resource for the next.At the close of the episode, Prince William introduces the finalists for the first ever Earthshot Prize to Build a Waste-Free World, and he reflects on the entire series and the scale of the challenges that face us as a species.