We can give them no other information except that we do not know: We do not know where it comes from, we do not know how you get it or why it kills you, but we know that it will. Epidemiologists have determined that here in Mexico most persons with idiopathic pulmonary fibrosis will die within 2 to 3 years of their diagnosis. As physicians, we are left to do the only thing we can, which is to ask: “How many months of your life have you lived within the municipal limits of Mexico City? Have you ever seen cockroaches, mice, or rats in your house? Do you have any pets, and if so, what kind and how many? Have you ever smoked cigarettes, cigars, marijuana, or crack cocaine?” We ask question after question, shots in the dark, each seemingly haphazard and misplaced. We write protocols and questionnaires and apply for funding and write reports. The study participants, or cases as they will be ultimately considered, are at the end stage of their disease. Coughing and fibrosing, with looks both of hope and exhaustion, they are dying.