Panic in Level 4

Introduction: Adventures in Nonfiction Writing

OLIVER HEAVISIDE, the English mathematician and physicist, once said, “In order to know soup, it is not necessary to climb into a pot and be boiled.” Unfortunately, this statement is not true for journalists. As a writer of what’s called “literary nonfiction” or “creative nonfiction”—narrative that is said to read like a novel but is factually verifiable—it has often been my practice to climb into the soup. Getting boiled with your characters is a good way to get to know them, but it has occasionally led me into frightening situations.

Some years ago, while I was researching The Hot Zone, a book that focuses on the Ebola virus, I may have had a meeting with an unknown strain of Ebola. (A virus is an exceedingly small life-form, an infectious parasite that replicates inside living cells, using the cell’s own machinery to make more copies of itself.)

Ebola has now been classified into seven different known types. Though it has been studied for more than thirty years, Ebola is one of the least-understood viruses in nature. Scientists have been understandably reluctant to study Ebola too closely because it has on occasion killed those who tried to do so. The virus was first was noticed in 1976, when it surfaced in Yambuku, Zaire (now the Democratic Republic of Congo), near the Ebola River, where it sacked a Catholic mission hospital, killing most of the medical staff along with a number of patients and people the patients had came into contact with. Ebola spreads from one person to the next by direct contact with blood or secretions, including sweat. There is no evidence that it can spread among humans through the air, although there is some evidence that it may spread among monkeys this way. As a parasite, Ebola carries on its life cycle in some unidentified type of animal—Ebola’s natural host—that lives in certain unidentified habitats in equatorial Africa. Occasionally Ebola comes into contact with a person, and the virus makes what is known as a trans-species jump from its host into the human species.

When Ebola gets inside a human host, it causes the person’s immune system to vanish, and the person dies with hemorrhages coming from the body’s orifices. The most lethal strains of Ebola have been known to kill up to 95 percent of people who become infected with it. Ebola causes people to vomit masses of black blood with a distinctive “coffee grounds” appearance. Victims can have a bright red nosebleed, or epistaxis; it won’t stop. A spotty, bumpy rash spreads over the body, while small, starlike hemorrhages appear beneath the skin. An Ebola patient can have blood standing in droplets on the eyelids and running from the tear ducts down the face. Blood can flow from the nose, mouth, vagina, rectum. The testicles can become infected with Ebola and can swell up or be destroyed. Victims display signs of psychosis. They can develop endless hiccups. Rarely, in particularly severe cases of Ebola, the linings of the intestines and rectum may come off. Those membranes may be expelled through the anus in raglike pieces called casts, or the intestinal lining can emerge in the form of a sleeve, like a sock. When an Ebola patient expels a sleeve, it is known as throwing a tubular cast.

SOME OF THE ACTION in The Hot Zone takes place at Fort Detrick, an Army base in the rolling country along the eastern flank of the Appalachian Mountains in Maryland, an hour’s drive northwest of Washington, D.C. The Army’s Level 4 virus laboratories at Fort Detrick are clustered inside a large, nearly windowless building that sits near the eastern perimeter of the base. This building is the headquarters of the United States Army Medical Research Institute of Infectious Diseases, or USAMRIID—a facility that Army people often simply refer to as “the Institute.” While I was visiting USAMRIID, or the Institute, to interview various experts in Ebola, I began asking officials at the base for permission to put on a biohazard space suit and enter one of the Army’s Biosafety Level 4 virus laboratories. I wanted to get a firsthand look at researchers handling Ebola. More than that, I wanted to know what it feels like to wear a biohazard space suit and be face-to-face with a real Level 4 virus, so that I could get a sense of my characters’ feelings and experiences, and could describe them with convincing precision. (Many nonfiction writers refer to their characters as “subjects,” but I prefer to think of them as dramatis personae in a true story.)

Biosafety Level 4, also called BL-4 or Level 4, is the highest and tightest level of biosecurity in a laboratory. Laboratories rated at Biosafety Level 4 are the repositories of viruses called hot agents—lethal viruses for which there is no vaccine or effective cure. Level 4 labs are sealed off from the outside world. People who go inside a Level 4 lab are required to wear a biohazard space suit, a pressurized whole-body suit, like an astronaut’s, made of soft, flexible plastic, typically blue. Army researchers sometimes refer to the space suit as a “blue suit” because of its color. A soft, flexible helmet that completely surrounds the head is joined to the suit, and the helmet has a clear, flexible plastic faceplate in it; the suit also has an independent air supply. The air supply prevents you from breathing the air inside the lab, which could be contaminated with a hot agent. Ebola virus is classified as a Level 4 hot agent, one of the most dangerous known, and it has the potential to be used as a biological weapon. The scientists at USAMRIID (it’s pronounced “you-SAM-rid”) conduct research into vaccines and drugs that could be used to protect the population of the United States against a terrorist or military attack with a biological weapon, including Ebola virus. This is medical research, peaceful in nature.

The Level 4 labs inside the Institute consist of groups of interconnected rooms. Each group of rooms is known as a hot suite or a hot zone. Each suite is sealed off from the outside world and is accessible only through an air lock. The air lock has heavy, stainless steel doors. Inside the air lock there is a chemical decontamination shower, also known as a “decon” shower. The purpose of the decon shower is to sterilize the outer surface of the space suits of researchers who are leaving a hot zone, to prevent a hot agent from getting a ride to the outside world. Chest freezers inside the Army’s hot zones are filled with collections of microvials (tiny plastic test tubes the size of a pencil stub) that contain frozen or freeze-dried samples of many different strains of lethal viruses.

The freezers are kept at 95 degrees below zero Fahrenheit. They are said to be hot. They are hot in a biological sense: they contain frozen samples of lethal viruses that are held in suspended animation in the extreme cold. The virus collections stored in USAMRIID’s hot freezers are said to include strains of Bolivian hemorrhagic fever virus, Guanarito virus, Junín virus, dengue hemorrhagic fever, Venezuelan equine encephalitis (VEE), Japanese encephalitis virus (JEV), Hendra virus, Nipah virus, Lassa virus, and the seven known types of Ebola. (These viruses’ effects on humans vary. Guanarito, Junín, and Lassa, for example, cause hemorrhaging from the body’s orifices, like Ebola. VEE and JEV infect the brain and spinal cord, causing coma or death. Nipah is a brain virus from Malaysia that can trigger a literal meltdown of the brain. The brain of a Nipah victim can be semiliquefied as the virus consumes it, and can pour out of the skull during an autopsy.) The hot freezers also may contain (although the Army doesn’t say much about this) an assortment of Level 4 Unknown viruses, or X viruses. The Unknown X viruses appear to be lethal in humans, but little is known about them. They’ve never been fully studied or classified. They may include something known as the Linköping Samples, which may or may not harbor an unidentified type of Ebola. The X viruses are presumed to be potentially lethal, so they are kept in Level 4 for safety.

We know that Ebola virus was one of the more powerful bioweapons in the arsenal of the old Soviet Union. In the years before the Soviet Union broke up, in 1991, bioweaponeers had reportedly been experimenting with aerosol Ebola—powdered, weaponized Ebola that could be dispersed through the air, over a city, for example. The Soviet weaponized Ebola was apparently stable enough that it could drift for distances in the air and still infect people through the lungs when they breathed a few particles of it. This is why the U.S. Army was studying it: the Army researchers were trying to come up with a vaccine or a drug treatment for Ebola, in case of a terrorist or military attack on the United States with Ebola.

As a natural disease, Ebola virus does not seem to be able to pass from person to person through the air, though. In each of the natural Ebola outbreaks, the disease seems to burn itself out, and Ebola fades away and is lost in the backdrop of nature, until, once again, by chance, it finds its way into a human host.

ONE DAY I WAS INTERVIEWING the commander of Fort Detrick. We were getting toward the end of the interview, and I decided to ask one last question. “I’d like to try to convey to readers what it really feels like to be face-to-face with Ebola virus.” I said. “Could I go into Level 4?”

“That should be no problem,” the commander answered promptly. “We’ll get you outfitted in a blue suit,” he said, “and walk you through Suite AA-4”—one of the Ebola hot zones. “It’s down and cold,” he added.

“What do you mean by ‘down and cold’?” I asked.

He explained that the hot zone had been completely sterilized with gas and opened up for routine maintenance. The rooms weren’t dangerous. Anyone could go into the lab without wearing a space suit. The hot freezers, too, had been moved out of the lab. Therefore, the lab was completely cold and safe.

“That’s not really what I had in mind,” I said.

“What did you have in mind?” he asked.

“I would like to experience the real thing, so that I can describe it. I’d like to go into a hot BL-4 lab and see how the scientists work with real Ebola.”

“That’s not possible,” he answered immediately.

Security at USAMRIID was extremely tight. Even so, it was not as tight as it would become. That day in the commander’s office was some nine years before the anthrax terror attacks of the autumn of 2001, shortly after 9/11. The anthrax attacks came to be known as the Amerithrax terror event, after the FBI’s name for the case. Small quantities of pure, powdered spores of anthrax—a natural bacterium that has been developed into a very powerful bioweapon—were placed in envelopes and mailed to several media organizations and to the offices of two United States senators. Five people died after inhaling the spores, while others became critically ill; some of the survivors have never fully recovered. For the most part the victims, including African-Americans and recent immigrants to the United States, were low-level employees of the post office who were just doing their jobs. No one has been charged with the Amerithrax crimes. The evidence suggests they were done by a serial killer or killers who intended to murder people and may have taken pleasure in causing the deaths while escaping punishment. The case remains open.

Officials at the United States Department of Justice named Steven Jay Hatfill, a former researcher at USAMRIID, as a “person of interest” in the case. Hatfill has never been charged with involvement in the crimes, though. At the same time, there was speculation in the news media that the exact strain of anthrax used in the attacks might have come out of an Army lab, even possibly from USAMRIID itself, where defensive medical research in anthrax had been going on for years. (The precise results of the FBI’s analysis of the anthrax strain have not been disclosed by the government, as of this writing.) USAMRIID scientists, in fact, played a key role in the forensic analysis of the anthrax that was collected from the envelopes.

Following the Amerithrax terror event, security at USAMRIID became astronomically tight. After that, it would have been useless for a journalist to ask to go into the space-suit labs. Back at the time when I was researching The Hot Zone, though, there was a slight amount of flexibility in the policy. On certain occasions, the Army had allowed untrained or inexperienced visitors to go into hot zones at USAMRIID. Unfortunately, as the commander explained to me, some of these visits had ended badly. People who were not familiar with space-suit work with hot agents had a tendency to panic in Level 4, he said.

In one such an incident, a medical doctor—a visitor—who had apparently never worn a biohazard space suit attended a human autopsy in a Level 4 morgue at the Institute. This hot morgue is called the Submarine. The Submarine is a sealed hot zone with an autopsy room and an autopsy table. The cadaver was believed to be infected with a Level 4 Unknown X virus. During the examination, while the space-suited autopsy team was removing organs from the cadaver, some members of the team noticed that the visiting doctor’s face seemed red. As the team members looked at him through his faceplate, they saw that his face was also dripping with sweat. Meanwhile, the outer surfaces of his space-suit gloves and sleeves were smeared with blood from the cadaver.

Reportedly, the man began saying, “Get me out!” Suddenly he tore off his helmet and ripped open his space suit, gasping for breath, taking in lungfuls of air from the hot morgue.

The members of the autopsy team took hold of him and hurried him to an air lock door leading to the exit. They opened the door, pushed him into the air lock. At least one of the team members accompanied him into the air lock. The air lock was closed, and the chemical shower was started.

The way I heard the story, the man stood or sat in the air lock while the chemicals ran down inside his opened space suit. The shower stopped automatically after seven minutes. The chemicals had flooded his suit. Then the team members helped him into the staging area—the so-called Level 3 area—and helped pull him out of his space suit. By this time, he was subdued and embarrassed.

At USAMRIID, people who have had a verified exposure to a hot agent are put into a Level 4 quarantine hospital suite called the Slammer. The Slammer is a biocontainment unit where doctors and nurses wearing space suits can treat a patient without being exposed to a virus the patient may have. The man who had panicked was a possible candidate for quarantine in the Slammer. Even so, after an immediate review of the incident by a safety team, the Army felt that he did not need to be put in quarantine; there was no evidence that the cadaver had actually been infected with a virus. And the man never got sick.

“We can’t predict how someone who’s untrained might react in BL-4, so we can’t allow you to go in,” the commander explained to me.

I still wanted to go into Level 4. But I couldn’t see how to get there.

IN NARRATIVE NONFICTION WRITING, taking notes is an essential part of the creative process. We tend to think of a reporter’s notes as being a transcript of the words of someone speaking to the reporter. If you who are reading this happen to be a student of journalism, remember that you can take notes about anything. It can be quite useful to jot down observations on any and all details of a person and a scene, including sights, smells, and sounds, as well as the emotional aura of the scene. These kinds of observed details might be called deep notes. Deep notes are a record of the visceral reality in which the characters exist—notes on the soup. Deep notes can be details of how people move their bodies, what they wear, what sorts of tics and gestures they display. I always try to note the color of a person’s eyes, and, when possible, I try to observe their hands.

One of the main figures in The Hot Zone is Lieutenant Colonel Nancy Jaax, an Army space-suit scientist who specializes in Ebola virus. I met Nancy Jaax during my first visit to Fort Detrick, on a warm spring day. She turned out to be a pleasant, energetic, articulate officer who seemed incredibly committed to her work. I learned that she was a mother of two children, who were then in high school. Her eyes were blue-green and active, with flecks of gold encircling the irises. About fifteen minutes into my first interview with her, I asked her if she had ever had a scary experience with Ebola virus. “Oh, sure,” she answered. “That’s where you realize that habits can save your life.”

“What sort of habits?” I asked.

She explained that when you’re working with a hot virus like Ebola, it’s essential to constantly check your space suit. A suit can get a hole in it. The person inside the suit might not notice the creation of the breach. Nancy Jaax had been trained to frequently check her space suit for leaks. One day, she was cutting open a dead Ebola-infected monkey, and her space suit was splashed with Ebola-infected monkey blood up to the forearms. Then, during a routine safety check, she discovered a hole in the arm of the suit, near the glove. Ebola-infected blood had run down into the hole and was oozing around inside her space suit and had soaked her arm and wrist. “I had an open cut on my hand, with a Band-Aid on it,” she said. She’d gotten the cut opening a can of beans for her children. The incident “fell into the category of a close call,” she said. In the end, she survived her encounter with Ebola only because her habit of checking her space suit for leaks enabled her to get out of the hot zone fast and remove her bloody space suit. Her narrative left me mesmerized.

There’s a useful technique for capturing important moments during an interview that I call the delayed note. When someone is saying something powerful, you don’t always want to draw attention to the fact that you’re writing down their words, because they may pull back and stop talking. So, on rare occasions, I may stop writing. I put down my notebook. I try to get a neutral expression on my face, as if I’m not that interested. Meanwhile, I’m trying to memorize exactly what the person is saying. When I sense that my short-term memory is getting full, I change the subject and ask a question that I expect will result in a dull answer. The person begins giving the dull answer, and I begin jotting delayed notes in my notebook. I’m writing down what the person said moments earlier, while I was not taking notes. (I learned this technique from John McPhee, who teaches an undergraduate writing course at Princeton University called The Literature of Fact. I had taken his course as a graduate student.) So, as Nancy Jaax began to talk about the blood in her space suit, I put down my notes and listened.

This was just the beginning of the research for a key scene in The Hot Zone, narrating how Nancy Jaax got a hole in her space suit and Ebola blood flowed inside it. At one point, much later, I spent twenty minutes sitting with Jaax at her kitchen table, taking notes on her hands. I examined her hands minutely, left and right, back and front, staring at them like a palm reader. Hands are a window into character. Jaax kindly submitted to my study of her hands, though I think it weirded her out just a little.

“Where did you get that scar on your knuckle?” I asked.

“Which one? That one? That’s where a goat bit me when I was nine,” she answered, touching the scar. It had been a goat on her family’s farm in Kansas, she explained, and she could still recall how much the bite had hurt.

Deep notes can also be notes on what a person is thinking. Of course, since you can’t read minds, you have to ask people what they are thinking or were thinking. After I’ve written a passage describing a person’s stream of thoughts—a type of narrative that fiction writers refer to as interior monologue—I always fact-check it with the person later. I read the passage aloud, usually on the telephone. I ask the person, “Do these sentences accurately reflect your recollection of what was going through your mind at that moment?”

Often, the person answers, “Not exactly,” and proceeds to correct what I’ve written to make it more faithful to their own memory. If it was an especially dramatic, emotional, or terrifying moment, the person can often give a consistent account of what they were thinking and feeling. (Witnesses to crimes often don’t accurately remember the facts of what they saw—but they do remember their feelings with clarity.)

After Jaax had realized that Ebola blood was slopping around inside her space suit, she had to make an emergency exit from Level 4. She went into the air lock and stood in the chemical shower, feeling the blood squishing around on her arm and hand.

“Were you thinking you would die?” I asked her.

“No,” she replied. Instead, she had been thinking about the fact that she had forgotten to go to the bank to get money for the babysitter who was taking care of her kids that day. If she was infected with Ebola, the authorities would lock her in the Slammer, and who was going to pay the babysitter?

I don’t think a novelist would be likely to invent this. And if it appeared in a novel, it might not ring true. Yet Jaax’s account of what she was thinking is completely believable because it occurs in a nonfiction narrative. It seems to reverberate with general human truth. It is a statement about mothers, children, and death, and it cut me to the heart when I heard it. I could not have made it up.

In the bloody space-suit scene, when Nancy Jaax emerged from the chemical shower and took off her suit to examine her hand, to see if there was any Ebola blood on it, I described her hands in detail as her gloves came off. Just a couple of sentences. These sentences were the result of the long examination of her hands at her kitchen table. I mentioned the scar on her knuckle and that she’d gotten it as a girl from a goat bite at her family’s farm in Kansas. The scar was a microstory. It told the reader that Nancy Jaax was a Kansas farm girl; she was Dorothy in Level 4.

While I often take photographs to supplement my notes, I almost never use a tape recorder. Apart from the fact that a tape recorder always seems to fail when it’s most needed, the device makes the person who’s being recorded self-conscious. An interviewee will stare at the tape recorder while his or her speech becomes awkward, not like the natural, lively voice of a person in real life. Indeed, cameras and sound recorders aren’t sufficient for deep notes. No electronic recording device can capture the interplay of the human senses. For capturing sensual reality, it seems that only an old-fashioned reporter’s notebook has sufficiently advanced technology. I take notes in longhand in little spiral notebooks. They are small enough to fit in a shirt pocket. I use a mechanical pencil.

TWO ARMY VIRUS RESEARCHERS walked down one of the long corridors of USAMRIID, at Fort Detrick. I had been hanging around with them that day. My shirt pocket had a magnetic security card clipped to it, with the word VISITOR on it. My shirt pocket also contained a small reporter’s notebook and a mechanical pencil. The walls of the corridor were cinder block, painted the color of sputum. Thick glass windows looked into sealed laboratory suites—Biosafety Level 2, Level 3, and Level 4. The corridor was filled with a weird, burning, moist smell. This smell, which will never leave my mind, was the odor of giant autoclaves—huge, pressurized steam ovens, full of equipment and waste from the labs, cooking the stuff at high heat and pressure, to make it sterile.

The researchers’ names will be given here as Martha and Jeremy; those are not their real names.

Jeremy glanced at Martha. “I was thinking it might be a good day for going into BL-4,” he said.

“I was thinking so, too,” she answered. She was looking at me.

Jeremy turned to me and said, casually, “Are you up for BL-4 today?”

We were standing before an inconspicuous door marked AA-5. It led to one of the Ebola suites, a group of rooms where Ebola research was actively being done. “What will we be doing in there?” I asked.

“Somebody died,” Jeremy answered ominously. “The blood samples came in the other day. We’re doing tests to try to identify any virus in the samples.”

The dead person’s identity had not been disclosed to the Army researchers. They had been told he was a “John Doe” male. He had apparently been a U.S. government employee. He might have been a soldier. Or he might have been a diplomat. Or, possibly, John Doe had worked for an intelligence agency such as the CIA. The researchers would never learn his name, the circumstances of his death, where he had died, or who his employer had been.

The Institute had relationships with various U.S. government agencies and offices. They were known as clients. The Institute’s clients included the White House, the Department of Defense, and, almost certainly, a number of intelligence agencies. The Institute performed research for its clients. Whichever client John Doe had worked for, he had died with symptoms that suggested a hot virus. His death had apparently involved tiny, starlike pools of blood under his skin, and blood might have been flowing from his orifices.

“I don’t know where the samples came from,” Jeremy said. “They didn’t tell me. Maybe the Middle East. The X virus, if it’s there, seems to be Marburg-like.”

Marburg virus is a type of Ebola that is associated with Kitum Cave, in the rain forest on the eastern side of Mount Elgon, an extinct volcano in East Africa. On at least two occasions, people who went inside Kitum Cave died shortly afterward of Marburg virus, having apparently caught the virus inside or near the cave.

“If there’s a virus in the blood samples, it’s considered a Biosafety Level 4 agent,” Jeremy continued. “This is because the guy died and because it [the putative X virus] hasn’t been identified. It’s an Unknown,” he said.

Martha swiped her ID card across a sensor, and a computer-synthesized voice issued from a speaker by the door: “RTU downloading.” There was a chime. “One moment please,” the computer said. A green light went on, and there was a click. The entry door had unlocked.

Martha went through the entry door and closed it behind her. The light over the door went from green to red.

Meanwhile, Jeremy and I waited in the corridor. Beyond the door was a locker room. Martha would take off all her clothing in the locker room and then would proceed inward through some other rooms, where she would put on her space suit and head into the Ebola zone.

In a few minutes, the light turned green again. This meant that Martha had left the locker room and had gone farther inward. Now we could enter.

Jeremy swiped his security card on a pad by the door, I swiped mine, and we entered the locker room. As we went into the room, we passed through an additional security system that won’t be described here.

In the end, I never found out what role the commander had in my visit to Level 4. But I think he must have known about it. Jeremy and Martha were experienced, cautious professionals with impeccable safety records. I speculated that the commander had decided to permit me to visit Level 4 with these two people, so long as the visit was kept low-key—though not unofficial. The main building of USAMRIID had security guards who sat in a control room, monitoring the movements of people in the building. I guessed that the security people had known that I would be going into a hot zone even before I knew it myself. The magnetic security card that I wore clipped to my shirt could show the security staff my location in the building; it would also tell them that I was entering the hot area.

The locker room was small and gritty-looking, with a wooden bench and some steel gym lockers, banged up and dented. Jeremy and I stripped down to nothing and put our clothing in the lockers.

“You need to take off your glasses and leave them, too,” he said. “They’d fog up inside the suit, anyway.”

People had to take out contact lenses, as well. They also had to remove jewelry, including engagement rings. (Women were allowed to wear a tampon in Level 4, but they had to remove it on their way out of the lab.)

I put my glasses in the locker. As I took off my shirt, I slipped the notebook out of my pocket, and I clipped the mechanical pencil to the notebook. Holding these two items, but otherwise stark naked, I followed Jeremy through a doorway that led inward.

The doorway was actually a tiled shower stall, with a water shower-head in it and a drain in the floor. The shower stall glowed deep purple with ultraviolet lights. On their way out of the hot zone, after having worked in a space suit with dangerous organisms, the researchers would pass naked through the water shower, washing their skin with detergent and bathing their bodies in ultraviolet light, before they went into the locker room to get dressed.

On the inward side of the ultraviolet doorway was a small room considered to be at Biosafety Level 2—the mildest degree of biocontainment. Some metal shelves stood against one wall, and there was a toilet. The shelves were piled with blue cotton surgical scrub suits and other items of surgical wear, along with rolls of tape. We put on scrubs—no underwear was allowed. We also put on white socks, surgical hair coverings, and surgical gloves. Jeremy showed me how to tape the socks and the gloves to the cuffs of my scrub suit, wrapping the tape around the cuff to make a seal. “It’s a good idea to empty your bladder,” Jeremy said. “You won’t get a chance to once you’re in a suit.”

I took up my notebook and pencil, and we pushed through a door into Level 3—this was a staging area leading to Level 4. It was a large room with cinder-block walls and a concrete floor. We heard a rumble of air-filtering machinery overhead. The staging area was crowded with pieces of laboratory equipment. Along the left-hand wall hung an array of biohazard space suits. They were made of soft blue plastic, with flexible plastic helmet hoods. Most of the suits had the owners’ names written on them with a Magic Marker.

“People are touchy about their suits,” Jeremy remarked. “It’s like the Three Bears: ‘Somebody’s been wearing my suit.’”

Martha had already donned her space suit, and she was preparing things in the staging area. While Jeremy got into his suit, Martha took a space suit down from the wall and helped me put it on. She opened the suit, peeling apart a sort of large Ziploc-style zipper that ran across the chest, and handed the opened suit to me.

There was no name on my space suit.

I sat down on a bench and slipped my feet through the chest opening, down into the suit’s legs. My feet ended up inside a pair of soft plastic bunny feet attached to the suit’s legs. I drew the suit over my body, and slid my arms into the sleeves, and into heavy rubber gloves attached to the ends of the sleeves.

I pulled the hood and faceplate down over my head. The space suit’s zipper ran diagonally across the chest. I sealed the zipper, running my thumb and fingers along the seal, which closed me into the suit. The zipper was coated with a kind of grease that felt like Vaseline. The seals made a lip-smacking sound as I squeezed the zipper shut.

A number of bright yellow air hoses dangled from the ceiling. They were the source of clean air for people’s space suits. Each room in the hot zone had its own set of air hoses hanging from the ceiling. When you moved from one room to another, you had to detach your air hose and get connected to a different air hose in the new room.

I reached up, grabbed an air hose, pulled it downward (it came down from a spring coil). I plugged the hose into a socket near my waist.

My suit inflated with a roaring sound. Cool, dry air began flowing around my body. The air was constantly being bled from exhaust ports in the suit, while the suit remained inflated. I felt the air blowing downward past my face, coming from vents inside the helmet. The airflow was designed to keep the suit under constant positive pressure, so that if the fabric developed a hole or a breach, air would flow out of the suit, and wouldn’t allow any dangerous organisms to flow in.

The high flow of air inside the suit created an almost deafening roar, which made it difficult to hear anything. The researchers had to shout to carry on a conversation in Level 4.

Jeremy closed his suit and pressurized it.

In front of us was a stainless steel door. It had a biohazard symbol on it, dark red, and the words

Martha took a hose and socketed it into her suit, pressurizing it. Then she turned and faced me. She placed herself between me and the steel door. Our suits bumped together. She pushed herself up against me until our faceplates made contact. “HOW ARE YOU DOING?” she asked. It was hard to hear her voice over the roar of the air.

“I’M FINE.”

She looked into my eyes. I thought she was examining me for any signs of claustrophobia—flushed skin, sweat standing on my face, wide staring eyes.

Evidently I looked all right. She caught Jeremy’s eye and stepped aside.

I took up my notebook and pencil, holding them awkwardly in one of my suit gloves, and we faced the steel door.

Martha looked down at my glove. “WHERE ARE YOU GOING WITH THAT NOTEBOOK?”

“IN THERE,” I shouted, indicating the door leading to Level 4.

She began laughing behind her faceplate. “IT’S FINE TO BRING YOUR NOTEBOOK INTO BL-4, BUT IT WILL NEVER COME OUT AGAIN. IT WOULD HAVE TO BE AUTOCLAVED”—cooked in a pressure oven. “THE PAPER WOULD DISSOLVE.”

So I couldn’t take notes. We would be in Level 4 for at least an hour. I wouldn’t be able to recall nearly enough. “I NEED SOME WAY OF TAKING NOTES. WHAT AM I GOING TO DO?”

“YOU COULD TRY THIS.” She handed me a sheet of flexible white plastic material, rather like paper, but, she explained, it was coated with Teflon. The researchers used this material in place of paper in a hot zone. You could write on it with a pen. It could be sterilized without damage.

“WHAT ABOUT MY PENCIL?” I asked. “CAN I TAKE THAT IN?”

“UH-UH,” Jeremy said, inspecting my mechanical pencil and shaking his head. “THAT’S GOT A SHARP TIP. PUNCTURE YOUR SUIT. SHE’LL GIVE YOU SOMETHING TO WRITE WITH WHEN WE GET TO THE HOT SIDE.”

When you moved from one room to another, you had to detach your air hose momentarily, walk without pressure in the suit, and then plug into the next air hose. As soon as the air hose was disconnected, your space suit would deflate.

Martha unclipped her air hose, and her suit went limp around her, shrinking down. She opened the steel door and stepped into the air lock and closed the door behind her. A moment later, Jeremy unclipped his air hose, and his suit went limp, and he stepped through the air lock door.

This left me alone momentarily in the staging room inside a pressurized suit. I looked back at the door we had come in through. I could do it. I could just leave. Open my space suit and climb out of it, and go back to the locker room and put my clothes on. These people wouldn’t care; they’d probably be relieved to see me go.

I unplugged my air hose. My space suit lost pressure and collapsed around me. Things got quiet: my air wasn’t running. I looked at the exit. Then I turned and opened the steel door and walked into the air lock. The door snapped shut behind me. At the far side of the air lock there was another steel door. I opened it and entered Level 4.

I FOUND MYSELF STANDING in a narrow corridor with walls made of cinder blocks. Martha and Jeremy weren’t in sight. I needed air. I looked up and saw a rack of air hoses hanging from the ceiling. I reached up and plugged a hose into my suit. The roaring noise began again, and a rush of air filled my suit, the suit tightening with the pressure. I looked around.

Several pairs of Christopher Robin–style rubber boots were lined up next to the air lock door. You were supposed to wear these boots in Level 4, to protect the bunny feet of the space suit from tearing as you walked around. I stepped into a pair of the boots, feeling nervous. The walls and floor were covered with thick-looking, beige paint—the paint was actually a layer of plastic resin that coated the inner surfaces of the hot zone, like the lining of a swimming pool, keeping it waterproof and airtight.

Martha appeared, coming around a corner. She plugged herself into an air hose. Then she handed me a Bic ballpoint pen. It was a Level 4 hot pen, and it would never leave Level 4, except as a melted lump.

Then we unplugged our air hoses and walked down the corridor. The rooms in Hot Suite AA-5 were small and cramped. They held typical laboratory equipment, the sort that you might find in any medical research lab in a university or corporation. I was struck by the ordinariness of Level 4. There were refrigerators, centrifuges, cabinets stocked with lab supplies. A couple of computers sat on counters. Nothing about the place suggested the presence of dangerous viruses, except for the unforgettable fact that we were inside space suits. There were sinks with water faucets. Wastewater from the sinks ran into collection tanks where the waste was sterilized. There was a room that had nothing in it except for two large chest freezers. They were hot freezers, hot as hell; I wondered if they contained Ebola, but I didn’t dare ask. The freezers were locked and were equipped with alarms. They could be opened only with combination keypads.

I followed Jeremy and Martha around a corner into a small room, where we plugged in our air hoses. Shelves and counters ran around the walls. A sign said:

The line had been left blank, since that day the researchers were working with an Unknown.

On one counter sat an incubator—a metal box that was kept warm inside, at a temperature of 37 degrees Celsius, which is 98.6 degrees Fahrenheit. The temperature of a human body. Martha opened the incubator and removed a rack full of small plastic flasks containing the Unknown. The flasks were sealed tightly with screw caps and contained a pinkish fluid. The fluid was a nutrient bath for a layer of living cells from the kidney of a monkey that were growing on a flat inner surface of each flask. Tiny drops of the blood of victim John Doe had been introduced into these flasks. If Doe’s blood contained a virus, the virus would be likely to infect the monkey cells. Then the cells would start dying—shriveling up and bursting—and this would be evidence that the flask contained a virus that had come originally from John Doe’s blood.

As yet, there was no direct evidence that John Doe had been infected with a virus. He might have died from some other cause. (Other illnesses, such as malaria, can mimic some of the symptoms of Ebola or Marburg, but we had to assume that John Doe had already been tested by doctors who’d ruled out the more common infections and illnesses.) It was the job of the researchers to determine whether the blood contained a virus and, if so, to try to identify it. This was detective work. The procedure was that of Sherlock Holmes: you rule out possibilities until only one possibility remains.

Martha wanted to look at the monkey cells to see if any of them showed signs of being infected with a virus. She sat down at a counter and placed one of the little flasks under a microscope. She did not open the flask. She stared into the eyepieces of the microscope through her faceplate, turning her head back and forth. “DO YOU KNOW HOW HARD IT IS TO GET YOUR HEAD COCKED SO YOU CAN SEE INTO A MICROSCOPE?” she yelled over the unending roar of air. She stood up. “DO YOU WANT TO LOOK?”

I sat down on the chair before the microscope. I had difficulty seeing through my faceplate into the eyepieces. I began twisting my head around. Finally I got a clear look through the microscope into the flask.

I could see glittering fields of monkey cells, reddish gold in color. Were they sick or healthy? They were just cells to me. As for the X virus, if any particles of it had been present in the cells they would not have been visible through the microscope. Virus particles are too small to be seen with an optical microscope. Most viruses can be seen only with an electron microscope, which magnifies things that are extremely small. A cold virus particle sitting at the base of an eyelash hair would be like a peanut sitting by the Washington Monument.

As I was staring into the eyepieces of the microscope, I felt a popping sensation. Something felt weird around my chest. My suit began to feel sloppy and loose. But I was interested in the cells and wasn’t paying attention to my space suit. Eventually, though, I moved away from the microscope and stood up. That was when I realized that my space suit had blown open in the hot zone.

AIR WAS RUSHING OUT around my neck and chest, pouring out of the suit. With a growing sense of alarm, I looked down to try to see what was happening, but couldn’t see anything. The lower part of my helmet hood blocked the view. I started feeling around with my gloves, but couldn’t get much sensation, for the gloves were thick and clumsy. I began tugging on something, some sort of fabric. To my horror, I realized that I was grabbing at my surgical scrubs. I was feeling around inside my space suit.

I knew what had happened. As I had been bending over the microscope, the movement had twisted the zipper that ran across the suit’s chest, and the lips of the zipper had pulled apart, and the pressure in the suit had opened it completely. And now I couldn’t get the zipper closed. I almost threw a tubular cast.

“DO I HAVE A PROBLEM HERE?” I yelled.

Jeremy had been working with his back toward me. He swung around, looked at me, and swore. He moved toward me, holding his palms outward. He ran his palms back and forth on my chest, closing the zipper.

My suit swelled up and tightened, regaining pressure.

“HOW BAD WAS THAT?” I asked.

He looked a little embarrassed. “THE ZIPPERS GET WORN. THEY CAN POP OPEN.”

I had ended up with a ratty old piece of Army gear, a space suit that belonged to nobody. A little voice started speaking in my head. What are you doing here? the voice said. You’re in an Ebola lab in a fucking defective space suit. I started to feel giddy. It was an intoxicating rush of fear, a sensation that all I needed to do was relax and let the fear take hold, and I could drift away on waves of panic, screaming for help.

Martha was looking into my eyes again.

The little voice went on: You’re headed for the Slammer.

Jeremy tried to soothe me. He assured me that the incident was not, in fact, an exposure to a hot agent. The suits did occasionally pop open, he admitted. “THE THING IS, YOUR SUIT HAD POSITIVE PRESSURE THE WHOLE TIME,” he explained. “THE AIR WAS FLOWING DOWN PAST YOUR FACE AND OUT OF THE OPENING. NOTHING COULD GET INTO YOUR SUIT. IT COULDN’T MOVE UP TO YOUR FACE.”

I really wanted to believe that an Unknown virus was not having an encounter with me inside my space suit. The air had been gushing out, I told myself. The flow would have carried any particles of a hot agent out of my suit. Anyway, if something had gotten in, by now it was too late to panic. I told the scientists that I wanted to remain in Level 4. After that, I touched my chest zipper frequently to make sure it was closed. Habits can save your life.

The researchers had work to do. Martha intended to open a flask of the Joe Doe Unknown. She carried one of the flasks to a Steriguard safety hood—a cabinet that produced a curtain of air blowing between the virus samples and the person sitting there. This air curtain acted as a shield, preventing any drifting particles from coming near the researcher. The cabinet also had a sliding glass door. If you opened the glass too far—potentially releasing a virus into the air of the hot zone—an alarm would go off.

With a pair of tweezers, Martha picked up a glass slide that had spots of reactive compound on it. It was called a spot slide. You drop liquid samples of virus on the spots, and if a spot changes color, it helps you identify the virus. “WE HANDLE GLASS WITH TWEEZERS BECAUSE YOU DON’T WANT TO PICK UP ANYTHING MADE OF GLASS WITH YOUR FINGERS,” she said. “YOU NEVER WANT TO CUT YOURSELF IN HERE.”

Martha opened the flask containing the Unknown. She took up a push-button pipette—a device that is used in biological labs for moving very small quantities of fluid from one place to another.

She inserted the tip of the pipette into the open flask and pushed a button, and the pipette sucked up a small amount of the liquid containing the Unknown X. She positioned the pipette over the glass slide and placed droplets of the liquid on the slide. Her hands moved with deft precision.

“DO YOU WANT TO TRY DOING THIS?” she asked.

I sat down in front of the safety cabinet. She handed me another flask. I had difficulty removing the cap from the flask. My heavy rubber space-suit gloves were impossible. I picked up the pipette and began dropping the liquid into a row of small test tubes, so that tests could be done on it. Even this simple task proved to be achingly slow and difficult. I couldn’t see how anyone could do medical research wearing Mickey Mouse gloves and a space suit. The fact that the Army researchers were able to do it every day made me appreciate the depth of their skill and training. My cheek began to itch, but I couldn’t figure out how to scratch it, since my head was inside a helmet hood. When I had finished the task, I closed the flask and held it up to the light.

The liquid shimmered inside; I was face-to-face with a presumed Level 4 Unknown. My cheek was itching badly. “HOW DO YOU DEAL WITH AN ITCH IN ONE OF THESE SUITS?” I asked.

“YOU DON’T,” Jeremy shouted above the unending roar of air.

Eventually the two researchers wrapped up a certain phase of their work. Thus far, they still had no information about what had killed John Doe.

Martha remarked that it was time to check on the monkeys.

“THERE ARE MONKEYS IN HERE?” I asked nervously. The little voice started up again: Are they infected? Go now to the exit.

Of course there were monkeys in here, Jeremy said. They had been vocalizing—screeching—the whole time, but the rushing sound of air in our space suits had drowned out their cries, he explained. He detached his air hose and began walking down a corrider, evidently heading for the monkeys.

“DO THEY HAVE BLOODY NOSES?” I asked.

The monkeys were fine, Jeremy said. He led me through a door into the largest room in Hot Suite AA-5. It was lit with flourescent lights. Along two walls of the room, stainless steel wire cages were stacked from floor to ceiling. Most of the cages were empty, but several of them held monkeys.

“THESE MONKEYS ARE SURVIVORS,” Jeremy said.

The monkeys were excited to see us. They raced back and forth in their cages, their eyes fixed on us. They were rhesus monkeys. Two of them sported wicked-looking canine fangs. (“Organ-grinder monkeys they aren’t,” one Army scientist had remarked.) The largest one, a male, bared his canines at me, staring at me with wide, fierce-looking eyes.

Martha came in. “THEY’RE MAKING THREAT DISPLAYS AT YOU,” she said. “THEY DON’T RECOGNIZE YOU.”

The monkeys could recognize human faces, even inside a space suit. The monkeys knew Martha and Jeremy, and seemed to look forward to their visits, for the humans fed the monkeys treats. The monkeys also seemed to find humans entertaining.

As a part of the Institute’s work in developing drugs and vaccines to protect humans against diseases, researchers exposed monkeys to viruses and then tested various treatments on them. Many monkeys died during such tests, but there were always survivors. “THIS MONKEY IS A SURVIVOR OF A COMBINATION OF SIMIAN HEMORRHAGIC FEVER AND EBOLA VIRUS,” Jeremy told me, pointing to one. “AND THIS ONE SURVIVED MARBURG VIRUS,” he said, pointing to another.

Marburg is the type of Ebola associated with Kitum Cave. The monkey that had survived a Marburg infection was about six years old, and his name was Eighty-seven. His odds of survival had been slim, but now he was healthy and very likely immune to Marburg. He was smart and easily bored. He yawned at us, exposing cruel-looking fangs.

Jeremy shuffled over to a shelf and got a box of Froot Loops cereal. Eighty-seven became excited.

Jeremy handed me the box and suggested that I give some of the cereal to Eighty-seven, to help make friends with him. I pulled a couple of Froot Loops out of the box. Keeping my eyes averted respectfully, for Eighty-seven was a dominant male and would become angry if I looked at him (in monkey language, staring is the equivalent of giving the finger), I placed the Froot Loops on my palm and held out my hand. The monkey’s arm shot out of the cage, and he plucked the cereal from my palm and crammed it into his mouth, and then held out his hand for more. He might have been able to tear my space suit if he had wanted to, but once I had offered him Froot Loops he became friendly. I offered him more Froot Loops. He kept shoving his hand out for more. A Froot Loop fell to the floor, and Eighty-seven followed it with his eyes, looking wistful, I thought. He put out his hand for more.

The Army people had become fond of the monkeys. Their feeling was that any monkey that had survived Ebola should be allowed to live out the rest of its days in peace. In addition, the survivors’ blood contained immune antibodies to the viruses, which could be used in experiments. But the monkeys could not leave the hot zone, because there was a worry that they might still be silent carriers of the viruses that had once infected them. “BASICALLY, NOBODY KNOWS MUCH ABOUT EBOLA OR MARBURG, SO WE DON’T KNOW IF THE MONKEYS COULD INFECT ANYONE WITH THESE VIRUSES EVEN AFTER THEY’VE RECOVERED FROM THE DISEASE,” Jeremy said.

We said good-bye to the monkeys and returned to the laboratory rooms. Finally it was time to make an exit from the hot zone. I followed the researchers through the maze of corridors and little rooms to the air lock.

Jeremy entered the air lock first and started the chemical shower by pulling on a chain. The shower began running in the air lock, sterilizing the outside of his space suit. While Martha and I waited for Jeremy to finish his chemical shower, I handed her my Level 4 Bic pen. She left it near a computer for the next person to use. Then Martha and I went into the air lock together. She pulled the chain and we stood under the chemical shower. The chemicals gave off a strong but not unpleasant smell, which eventually crept inside my space suit.

Martha pointed to my Teflon paper—my notes—which I held clutched in my glove. “LET ME HAVE THAT FOR A SEC,” she said. She crumpled it up, dipped it into a bath of chemicals, and then, using both hands, she scrubbed the Teflon paper against itself and squeezed it, as if she were rinsing a washrag. After a minute or so, she pulled the paper out of the chemical bath. My notes were wrinkled, wet, and sterile. The shower stopped, and I opened the steel door and stepped into the normal world, holding the notes.

Later, I wrote about Nancy Jaax’s feelings after she had gotten a hole in her space suit and she was standing in the chemical shower, feeling Ebola blood oozing around inside her suit and wondering who was going to pay the babysitter. I constructed the passage primarily from detailed interviews with Nancy Jaax, of course. Yet there is something else in that scene that did not appear in the book. It was an iceberg of personal experience, one I hadn’t felt able to write about until now. I had been in the rooms she had been in. There, I had experienced a breach condition in my space suit, too, and it had happened in the presence of a putative hot Marburg-like Unknown. And I had stood in the same chemical shower afterward, with thoughts and fears pouring through my mind…. I had been boiled in the soup.

I LOVE EXPLORING UNSEEN WORLDS. In this book, we are embarking on a deep probe through the realms of the vanishingly small, where, at times, all we can say is “There be monsters.” The chapters in this book were originally published in The New Yorker, but I’ve expanded, updated, and linked them.

One monster of the microscopic universe is a mysterious genetic disease, called Lesch-Nyhan syndrome, which is caused by the alteration of a single letter of a person’s DNA code. If one letter of the human DNA is altered in a certain place in the code, the person who is born with the tiny error has a dramatic change of behavior—a lifelong, irresistable compulsion to attack himself, chewing off…it’s in the last chapter.

“The Mountains of Pi” describes David and Gregory Chudnovsky, mathematicians who built a supercomputer out of mail-order parts in Gregory’s apartment in New York City. They were using their homemade supercomputer to calculate the number pi (π) to billions of decimals. They were looking deep into pi, down into an infinitesimal smallness of precision, deeper and deeper into pi, trying to get a glimpse of the face of God.

I originally wrote about the Chudnovskys in a “Profile” for The New Yorker. When I first met them and began researching the piece, they seemed pleased that I was writing about pi, but they soon got the idea that I was also writing about them. They began to object. “My dear fellow, can’t you leave our names out of this?” David said.

I had to explain that it is not really feasible to leave a person’s name out of a New Yorker “Profile” of him.

This puzzled me, why the Chudnovskys didn’t want their names used. The answer, as I finally figured out, had to do with the nature of mathematics as a human activity. Mathematics is not strictly science, nor is it absolutely art. Mathematics is both objectively rigorous and highly creative, and so it spans the divide between the two worlds, and expresses the unity of science and art. In effect, mathematics is a cathedral of the intellect, built over thousands of years, displaying some of the greatest achievements of the human spirit. The Chudnovsky brothers saw themselves as anonymous workers adding a few details to the cathedral. Their names didn’t matter.

When I had finally gotten their reluctant assent to let me write about them as people and had finished drafting “The Mountains of Pi,” a fact-checker from The New Yorker named Hal Espen paid a visit to the Chudnovsky brothers in order to verify the facts in my piece. Soon afterward, Gregory phoned me in a state of indignation. Hal Espen had spent a long time in Gregory’s apartment, looking at the things I’d described and asking the brothers many questions. At one point, he wanted to confirm that Gregory owned hand-sewn socks made of scraps of cloth, as I had written, so he asked Gregory if he could see his socks. Gregory wasn’t wearing them, so Espen ended up looking in one of the drawers of Gregory’s dresser, where he found the socks and verified my description of them. “He was a nice guy, but why did he have to rifle through my socks?” Gregory demanded.[1] If the names of the cathedral workers didn’t matter, their socks mattered even less. But Gregory Chudnovsky’s socks mattered deeply to me, for the same reason that the color of Nancy Jaax’s eyes and the scar on her hand mattered. The business of a writer, in the end, is human character, human story. Unlike a novelist, a narrative nonfiction writer cannot make up details of character. For the nonfiction writer, details must be found where they exist, like diamonds lying in the dust, unnoticed by passing crowds.

In exploring biology, I moved my focus away from the smallest life-forms—viruses—and began climbing the coast redwood trees of California. The coast redwoods are the largest individual living things in nature. Redwoods can be nearly forty stories tall; they would stand out in midtown Manhattan. In order to climb a redwood, you put on a harness and ascend hundreds of feet up a rope into the redwood canopy. It’s like scuba diving, except that you go into the air. The canopy is the aerial part of a forest, and it is an unseen world, invisible from the ground. Once you have ascended into the redwood canopy, which is the world’s tallest canopy, you dangle in midair, in a harness, around thirty stories above the ground. You are suspended from ropes attached to branches overhead. You move through the air while hanging on ropes, sometimes going from tree to tree. The redwood canopy is a lost world, unexplored, out of sight, teeming with unknown life. After writing a book about it (The Wild Trees), I learned of the existence of an unexplored rain-forest canopy in eastern North America; I hadn’t known there were rain forests in the East. This eastern rain forest was being destroyed by parasites invading the ecosystem. It was an unseen world that was vanishing even before it had been explored by humans. Thus an interest in giant life-forms ended up returning me to a focus on small things: “A Death in the Forest.”

“The Search for Ebola” is about the search for the unknown host of the Ebola virus, and it narrates an outbreak of Ebola in Congo. In researching it, I ended up talking with a medical doctor named William T. Close. Bill Close, who is the father of the actress Glenn Close, had been the head of the main hospital in Kinshasa, the capital of Congo (then called Zaire). Then, while I was staying late in the offices of The New Yorker on a Friday night—closing time, when the magazine is put to bed—I telephoned Dr. Close for a last-minute fact-checking conversation. In about ten minutes (I had been told) the magazine would be closed—finished—and would be transmitted electronically to the printing plant in Danville, Kentucky. That was when Dr. Close told me the story of a Belgian doctor who had performed a terrifying act that could be called an Ebola kiss, with a patient in an Ebola ward.

“Oh, my God,” I blurted.

I asked someone to go find Tina Brown, the editor, and see if the magazine could be held open for a little while, as a doctor was saying something. It was okay with Brown, but there was no time to take notes. I asked Close to tell me the story again, while I scrawled sentences describing the Ebola kiss on a sheet of paper. With Close waiting on the line, I carried the paper over to the make-up department (an office where the magazine’s compositors worked at computer screens) and I handed it to Pat Keogh, the head of make-up, who typed my scrawl into the master electronic proof. Almost immediately, the passage was reviewed for grammar by The New Yorker’s grammarian, a quiet person named Ann Goldstein. (Experts who are being quoted in The New Yorker are encouraged not to use bad grammar.)

Minutes later, with Bill Close still waiting on the telephone, we heard that his grammar was okay, and we heard that the magazine had been transmitted electronically to the printing plant. I said good night to the now-eponymous Dr. Close and hung up.

That was when something struck me. How could I have been so stupid? I had forgotten to ask Close what had happened to the Belgian doctor afterward. He would have died a grisly death. Years later, I learned what had transpired, and you will read it here.

In “The Human Kabbalah,” I explored the decoding of the human DNA and the resulting fantastic stock-market bubble that made the genomic scientist J. Craig Venter a billionaire for a while. One day, while working on this story, I was hanging out in the laboratory of the Nobel laureate Hamilton O. Smith—one of the great figures in the history of molecular biology—and I mentioned to him that I was having trouble, as a writer, describing DNA in a physical sense. I wanted readers to get a concrete picture of it in their minds. “The trouble is, DNA is invisible,” I said to Hamilton Smith.

“No, it isn’t,” he said. He asked me if I’d ever seen it. I hadn’t, so he dribbled some purified DNA out of a test tube. It looked like clear snot.

“What does it taste like?” I asked him.

That surprised him a little. He didn’t know. In almost forty years of research with DNA, Hamilton Smith had never tasted the molecule.

As soon as I got home, I ordered some pure, dried DNA through the mail. It arrived: a bit of fluff in a bottle. I put some of it on my tongue. Sure enough, it had a taste. In taking notes, it is useful to remember that all the senses can be involved.

I continued to follow the Chudnovsky brothers and their journeys in the universe of numbers. This led them, with me trailing behind, to the mysterious Unicorn Tapestries, owned by the Metropolitan Museum of New York. All the while, I was researching the curious genetic disease that causes people to mutilate and even, in effect, cannibalize their own bodies—Lesch-Nyhan syndrome.

The disease was almost unbearable to contemplate, and at first almost impossible to describe. It made its victims seem inhuman. I couldn’t find a way into the writing of the story, despite spending months and finally years on it. Ultimately, the last chapter of this book took me seven years to write. The disease probably could not be invented by a fiction writer, or if it were invented, it would not seem believable. Yet there it was, an undeniable reality. I needed to understand, if possible, what it might feel like to have this disease. I wanted to try to connect the seemingly unknowable experience of self-cannibalism to that of common humanity. Henry Fielding, in his famous preface to his novel The History of Tom Jones, in which he defined the basic terms of fiction writing, quoted Terence: “I am human: nothing human is alien to me.” If people with Lesch-Nyhan disease were human, then they could not be alien to us. The only way to find humanity in the story was to climb into the soup with two people who had been born with the disease and start taking notes.