The Cobra Event by Richard Preston

smoked his cigar. “That’s all you need?”
    “Epi work is pretty simple,” she said. She looked out the window of his office. There wasn’t much to see, only the brick wall of the next building, but she observed that it had begun to rain. “I forgot to bring a raincoat.”
    “I’ll get you one of our slickers. And you’ll need an office, won’t you?”
    “I guess so.”
                      
    THEY GAVE HER a tiny office, almost a closet, on the third floor. Someone brought her a bright yellow rain slicker. Across the back in black letters it said, “ OFFICE OF CHIEF MEDICAL EXAMINER .” It was a disaster raincoat, meant for protecting workers from blood and body fluid splashed around a disaster site, as well as from rain. It smelled of sweat.
    The room was the office of a staff pathologist, a woman who was away on maternity leave. The office’s one window looked out on the blank wall of a parking garage some feet away. It was a nicer room than her digs in the C.D.C., anyway. She wondered why epidemiologists inhabited the world’s worst offices. She taped a map of New York City to the wall. With a pencil she marked an X on the map: at the location of the Mater School on Seventy-ninth Street, where Kate Moran had died. She marked another X on Times Square, where Harmonica Man had collapsed. The marks showed the
location
of death. They did not show where the victims had been exposed. If indeed they had been exposed to anything. If this was an outbreak of an infectious disease or a rash of poisoning, Harmonica Man was the first identified case. He was therefore what was known as the index case. Kate Moran, who died less than a week later, was the second case. There was no obvious connection between the two cases. It was not necessary for Austen to know what had killed them in order for her to begin an investigation. As Dr. John Snow knew, epidemiology can proceed without any knowledge of the nature of the disease-causing agent.
    Deeper

    KATE MORAN’S TISSUES were being processed in the O.C.M.E. histology lab, and they would not be ready for viewing for about a day. In the meantime, Harmonica Man’s tissues could be examined, and Austen called for samples, giving the case number to a technician. “Those slides have been checked out by Dr. Dudley,” he said. So she went down to Glenn Dudley’s office on the third floor and found Dudley sitting at a small table, staring into the eyepieces of a doubleheaded microscope. This is a microscope with two sets of binocular eyepieces, so that two people can look at a specimen at the same time.
    “What do you want?” Dudley said without looking up.
    “I wanted to take a look at the tissues of the first case.”
    He grunted and kept staring into his microscope.
    Austen sat down across from Dudley, facing him, and looked into the other set of binocular eyepieces. She saw a field of brain cells. It was a thin slice of Harmonica Man’s brain tissue.
    “It’s from the underside of the temporal lobe,” Dudley said. “The area of the hippocampus. It seems damaged.”
    She let her gaze relax. She wandered through fields of cells. She saw threadlike neurons, which are the nerve cells that send signals in the brain. She saw other types of brain cells, and she saw white matter, which is a fatty substance in the brain. She came to a damaged area, where she began finding red blood cells. “I think I’m getting into a bleeding spot.”
    “Nothing else? Okay, I’m zooming.”
    The scene jumped. The cells were magnified more strongly. “Look at these cells,” he said. “Zooming again.” The scene jumped forward. They were on a voyage, running deep into the brain of Harmonica Man.
    There was something wrong with the cells. A neuron, a nerve cell, is a long thread with branches. Somewhere in the middle of the thread there is a bulge. Inside the bulge there is a dot. The dot is the cell’s nucleus, where the cell’s genetic material is stored, its DNA. The