Mr. K. was forty-two and almost dead, kept alive by machines, tubes, and liquids that would at best give him two or three days more. His wife had brought him to the emergency room, probably because he was confused or vomiting or had chest pain. It soon became clear that he had taken too much Vicodin or heroin or any one of a number of potentially lethal drugs, perhaps by accident, perhaps not. No one knew for sure; he’d fallen unconscious soon after his arrival at the ER. We had only his lab results and his family to fill in the blanks, and they told different stories.