Charlotte Smith visits the Colne Valley Regional Park, a landscape of forest, fields and waterways on the edge of west London. She does battle with an invasive species, gets up close with tiny creatures that show the health of the park's rivers, meets a savvy septuagenarian saving her farm from development, and helps secure a future for one of our most endangered mammals, the water vole. Tom Heap asks whether eco-education should be at the heart of our school system, Adam Henson introduces new boar George II to his sows, and wildlife cameraman Jack Perks gets up close with otters.