London, 1851. This is Mary. She’s twenty-six years old. And she’s dying of typhoid. Again. This is her third time. She lives in a tenement house on Drury Lane. Forty-seven people share this building. They have: ∙ One toilet ∙ One water pump in the courtyard ∙ One cesspit that overflows constantly The house has had fourteen typhoid outbreaks in three years. Everyone knows the cesspit is contaminated. The landlord won’t fix it. Why? Because he doesn’t live here. He owns six tenements like this one. Repairs cost money. Tenants are replaceable. Mary pays three shillings a week for a single room. She shares it with her husband and three children. Five people in a space ten feet by twelve feet. The cesspit is six feet from the water pump. When it overflows—which is constantly—the waste seeps into the groundwater. Into the pump. Into the water they drink. This is how typhoid spreads. This is why Mary’s had it three times. This is why the house has had fourteen outbreaks. The landlord knows...