In towns and neighborhoods across the country, there are people who hold a single, irreplaceable skill — repairing church organs, hand-lettering storefront windows, butchering in the old way — and almost no one is learning from them. When they're gone, something goes with them that can't be googled or reverse-engineered. This episode asks what it means to let a piece of human knowledge quietly leave the world, and whether anyone has a responsibility to stop it.