The Demon in the Freezer

Lisa Hensley

On the first of September 1998, a twenty-six-year-old civilian scientist named Lisa Hensley reported to work for the first time at USAMRIID. She was a postdoctoral researcher with a fellowship from the National Research Council. Hensley rented a one-bedroom apartment in Germantown, about twenty minutes outside Frederick. She furnished the apartment with a couch and a television set that she had inherited from her grandmother.

Lisa Hensley is of medium height, with hazel eyes and dark brown hair that she usually wears tied back in a ponytail; when she’s working in the laboratory, she ties her hair up so that it won’t fall into her experiments. She has an open face, a calm, unruffled manner, and a rapid, precise way of speaking. She was an All-American varsity-lacrosse player at Johns Hopkins, and she has broad shoulders and an athletic way of moving. She usually wears khaki slacks, square-toed loafers, and gold earrings decorated with small pearls. She rarely takes off the earrings, even when she’s inside a biohazard space suit. Hensley is a scuba diver, and she likes to dive on wrecks and into underwater caves. Cave diving is not for people who get claustrophobia, and the sport has a high rate of accidents. She finds it calming, she says.

Lisa’s father, Dr. Michael Hensley, works in the pharmaceutical industry. When he was younger, Mike Hensley rode horseback and fenced with sabers, but during his medical internship he had what he describes as an interesting event — a hemorrhage. He learned that he had a mild form of hemophilia, a genetic disease that occurs only in men but is inherited through female carriers. Hemophilia ran in the Hensley family. Many men with hemophilia have died of AIDS, having received blood transfusions tainted with HIV during the years when blood wasn’t tested for it.

When Lisa was eight years old, HIV was just beginning to be understood. Mike Hensley received blood transfusions during that time, but he didn’t become infected. Lisa was extremely close to her father. He took her into his laboratory and taught her how to grow bacteria on petri dishes, and he gave her bottles of seawater to look at in his microscopes. She saw that a tiny droplet of the sea was an ecosystem packed with life. She told her parents that she wanted to be a marine biologist, and at twelve she was certified as a diver.

In high school, she was a jock who was bored out of her mind with her studies, including biology. She became a state-champion lacrosse goalie with a string of varsity letters, and applied to the U.S. Naval Academy to become an aviator. Then, at the last minute, she changed her mind and went to Johns Hopkins, which recruited her to play lacrosse.

At Johns Hopkins, Hensley began taking courses in public health. When she was a junior, Mike Hensley invited her to attend a scientific conference in San Francisco on HIV, and it electrified her. She became fascinated with the idea that if you really understood how viruses emerge, you might be able to stop a disease like AIDS before it could spread. She graduated from Johns Hopkins in four years with a master’s degree in public health.

Hensley went on to get a Ph.D. in epidemiology and microbiology in three years at the University of North Carolina at Chapel Hill, and at the same time she got a second master’s degree in public health. She had pretty much no social life in graduate school and devoted herself to the laboratory. She moved viruses from one type of host to another and watched trans-species jumps occur in the lab, before her eyes. She learned the standard methods of virus engineering — how to change the genes of a virus, altering the strain.

Hensley had an apartment across the street from her lab at Chapel Hill, so that she could spend nearly every waking minute in the lab, with the goal of having three advanced degrees by her twenty-fifth birthday. She didn’t sleep much, and when she did she had recurrent dreams, focused on her hands. In the dreams, she was working faster and faster, trying to finish an experiment, yet she could never make her hands go fast enough…. She was falling behind…. Her grant money was running out…. Life was too short…. And she would wake up. She’d grab a Diet Coke for breakfast and stumble across the street to the lab, where she would work all day and half the night.

At USAMRIID, Lisa Hensley began doing research on SHF, a Level 3 virus that is harmless to humans but is devastating to monkeys. It was a virus that could emerge as a human disease someday. Her social life had opened up, and she had begun dating a virologist at the National Institutes of Health in Bethesda, Maryland. Things didn’t work out well between them. The problem was that when they argued with each other, it was about viruses. Scientific people are competitive types, and they like to be right. Any sort of discussion about viruses with her friend could turn into an emotional fight. One time, they were in his apartment debating some minor point about a virus, and he said, “You’re wrong about that.” She went over to a shelf, grabbed a textbook, and opened it to the page that showed she was right. She placed it on the kitchen table and walked out. Hensley admitted to herself that this was perhaps not emotionally shrewd. When they broke up, she vowed to herself, No more scientists, they’re a headache.

The head of Lisa Hensley’s division at USAMRIID was Colonel Nancy Jaax, an experienced pathologist with a strong interest in Ebola virus. Hensley had zero interest in Ebola. The space suits at USAMRIID are blue, and from the day she arrived there Hensley made a point of saying, “The people who work in the blue suits are nuts. I’m not putting on a blue suit for Ebola. You have to be crazy to do that.”

Nancy Jaax heard about Hensley’s cracks about people who worked with Ebola being crazy. It was felt that cautious people would be less likely to have an accident in Level 4. The last thing anyone wanted was a researcher getting cocky around a hot agent.

One day Hensley walked into a regular staff meeting, in a windowless conference room on the second floor of the Institute, and, as a junior scientist, took her place at the foot of the table. The meeting droned on for a while, typically, until Nancy Jaax suddenly looked down the table at Hensley and announced that her mission was about to change. “I’m going to have you refocus your efforts, Lisa,” Jaax said. “We’ll get you trained in the blue suits, and we’ll start you working with Ebola Zaire.”

Lisa Hensley came out of the meeting feeling dizzy and a little unsteady on her feet. She teetered back to her cubicle and fell into a chair. The cubicle was a cluttered space, piled with papers. There was a computer, a stereo, and pictures of her mother and father and other members of her family. They’re going to start me with Ebola Zaire? she thought.

Death from Ebola comes about five to nine days after you break out with symptoms, and it occurs with spurts of blood coming from the orifices and a collapse of blood pressure, an event that Army people call the crash and bleed-out. In some cases, the virus causes a near-total loss of blood — an Ebola exsanguination. They were paying Hensley thirty-eight thousand dollars a year, but was it worth it? If you infected yourself with Ebola, that was it.

Hensley was closer to her parents than to anyone else in the world. Her mother, Karen, called her three times a week to find out how things were going. Lisa told her that the powers at the Institute had redirected her career into Ebola virus.

“You’re going into a BL-4 suite to work with Ebola? Isn’t there anything else they could have you do?”

Lisa tried to play things down. “Oh, Mother. I’m much safer in a space suit. Really.”

“Mike! Mike! Come talk to your daughter.”

Lisa’s father thought it was a good opportunity for her, and they decided to give Karen a tour of the laboratories, so she could see that everything was safe.

The tour wasn’t quite as successful as they had hoped. Karen Hensley is an economist, and she didn’t have a natural feel for biohazard containment. She noticed a door marked CRASH DOOR. That didn’t sound too good, but it was a safety feature. If a fire or other emergency occurs in Level 4, you can burst out through the crash door, and you end up standing in the hallway in your space suit. (So far, no crash door has been used for that purpose at USAMRIID.) What really bothered her was the fact that the edges of the crash door were sealed with brown duct tape, which ran all around the door frame. “Why do they have tape around that door, Lisa? Is that how they seal the doors around here? Just with tape?”

Lisa explained to her mother that the hot suites were under negative air pressure, and air was constantly flowing into the labs, so the tape was actually to prevent dust and contaminants from entering and messing up the experiments.

Karen Hensley didn’t like the look of the tape, period. Then she discovered what you wear inside a biohazard space suit: green cotton surgical scrubs, latex surgical gloves, and socks. That is all. Underwear is forbidden in a hot lab. Karen Hensley was mortified for her daughter. She could not imagine why they would make any woman work in a laboratory without a bra.

Hensley was trained in blue-suit work by an older postdoc at USAMRIID named Steven J. Hatfill, a big, muscular man in his forties with a mustache and a medical degree — a civilian medical doctor with a background in the U.S. Special Forces. He showed her how to put on the suit, how to do a safety check on it for leaks, how to maintain it properly, and how to go in and out through the decon-shower air lock in Level 4. Steve Hatfill was known around the Institute as a “blue-suit cowboy.” He seemed fearless in a blue suit, and he thrived in Level 4. He had a thirst for adventure: he had been a soldier in Africa, where he said he had served in Rhodesia with the white Rhodesian Special Air Squadron — the SAS — during the years when black insurgents were trying to overthrow Rhodesia’s white government. Later, he got a medical degree in Zimbabwe, and he worked as a doctor in Antarctica for a year and a half with a team of South African scientists. Hatfill had become convinced that a bioterror event was likely to happen. He served as a consultant to emergency planners in New York City, and he kept a strip of reflective tape on the roof of his car, so that in the event of a bioemergency the state-police helicopters could find him.

Lisa Hensley found Steve Hatfill likable and entertaining, quite a character. He was bright, a super lab worker, and he taught her some techniques. He was researching the coagulation of monkey blood infected with Ebola virus. Ebola blood became hemorrhagic and wouldn’t coagulate, but it needed to be clotted in the lab for study; he taught her how to do this. He had all kinds of gadgets running in Level 4—assay machines, that sort of thing.

During one of her first training sessions, Hensley looked over at Hatfill and noticed that he was hunched inside his space suit. One arm of his suit was hanging limp, as if he had had a stroke. At first, she didn’t know what was going on: was he suffocating or what? Hatfill had pulled his arm up inside the sleeve of his space suit, and he was eating a candy bar.

Lisa Hensley was a rising star at the Institute. Postdocs like her tended to move on quickly if they got bored, and she was assigned to work in Peter Jahrling’s group. Despite his growing involvement with smallpox and national policy, Jahrling had continued to do research into Ebola virus, working closely with Tom Geisbert. They not only were scientific collaborators but had become personal friends. Lisa Hensley went to work for Geisbert, who was running Ebola experiments in Level 4. She did lab work on samples of monkey blood infected with Ebola. On her own, she began developing tests for detecting the presence of Ebola virus inside individual cells. The tests made infected cells glow red or green under a fluorescent microscope. You could see how Ebola virus was invading cells in the immune system and doing clever things that seemed to trigger a cytokine storm. She was getting closer to understanding how Ebola overwhelms the human immune system. This was important work, because there might never be a vaccine or cure for Ebola unless scientists understood how it killed.

Hensley found that she liked the peaceful feeling of working alone in a space suit in Level 4, with nobody to distract her, nothing but the green cinder-block walls and her dishes of Ebola. She felt cozy inside the suit, even though the rooms around her were hot with the virus. It was like scuba diving. A space suit was a sanctuary from the hubbub of the world. You could do your work without being interrupted by people asking questions or calling on the telephone, and you could press a little deeper into nature.

Hensley was growing Ebola in virus cultures. Viruses are grown in plastic well plates containing a liquid cell-culture medium. In the bottom of the wells there is a carpet of living human cells, alive and bathed in the liquid. (The cells are HeLa cells, cervical-cancer cells derived from an African-American woman named Henrietta Lacks, who died in Baltimore in 1951. Her cancer cells have become a cornerstone of medical research and have saved many human lives.) Hensley would infect plates of cells with Ebola, and in a few days virus particles would begin budding out of them. Ebola particles are shaped like spaghetti, and they grow out of the cells like hair. The strands break off and drift away in the liquid. The virus is amplified in the well plate, and in a few days the liquid becomes a virus soup, rich with particles of Ebola.

Hensley became good at making amplified Ebola soups. Using a pipette, she moved droplets of Ebola soup around from well to well, from vial to vial. She would hold the pipette in her heavy yellow rubber gloves, push a button on the pipette with her thumb, pick up a small quantity of the Ebola soup, and then drop it into a vial.

Ebola soups are pale red, the color of a watered ruby, and sparkling clear. A well plate full of Ebola soup contains up to five million lethal doses of the virus — in theory, enough Ebola to make half of New York City crash and bleed out. Yet handling Ebola soup is no more dangerous than walking down a busy street. You could be killed if you stepped in front of a bus, but careful people watch where they are going. Hensley wore earplugs, and she heard nothing but the distant roar of cool, sterile air running in her space suit. It sounded like surf on a beach.

Hensley spent so many hours working in her suit with Ebola that she began to get those dreams again. In her Ebola dreams, she would be moving droplets of Ebola soup from well to well, from vial to vial, working faster and faster, trying to complete an experiment, and there was never enough time to find out what she longed to know about viruses. In her dreams, she was always in control of Ebola virus, and Ebola never had control over her.

Panic in the Gray Zone

Hensley was working alone in her blue suit in hot suite AA4, near the center of the Institute. It was about three o’clock in the afternoon. She had been working with soups of Ebola for many hours. She wasn’t feeling well: she had a cold and was a little achy, as if she might have a slight fever. She had probably caught a virus, but she was in the middle of an experiment, and she couldn’t abandon it just because she felt sick. She would lose her data if she went home.

She was holding a pair of blunt children’s scissors with her rubber space-suit gloves. (Sharp scissors are forbidden in Level 4.) She was trying to open a bottle by prying on a tab with the scissors. Suddenly, they slipped, and the tip of the scissors jammed into the middle finger of her right glove. She felt a stab of pain near her fingernail.

She held her space-suit glove in front of her faceplate. What had just happened? Had she cut the glove? The yellow rubber was wet, and as she turned the glove in the light, she couldn’t tell if there was a cut in the rubber or not.

Inside her space-suit gloves, she was wearing latex surgical gloves, for an extra layer of protection. Wriggling her arm, she pulled her hand out of the space-suit sleeve and up inside her space suit — the way Dr. Hatfill did when he ate a snack inside his suit — and inspected the latex glove at close range, inches from her eyes.

The rubber was translucent. Beneath it, she saw blood oozing out of her finger, moving along the fingernail. A red spot under the rubber was spreading along the cuticle. It hurt.

It is believed that a single particle of Ebola virus introduced into the bloodstream is fatal.

Hensley felt a sudden rise of fear, which turned into a little bit of panic. What was the last thing I touched with my hand? What was I doing? What were the scissors touching? Was there any soup on the scissors? The mind goes sticky in a moment of fear. She blanked. She couldn’t remember what she had been doing with her hands. There was nobody to ask.

She began to talk to herself silently: Quit panicking and calm down. Did I make holes in both gloves? Or did I just crush my cuticle? She stuffed her arm back down into the sleeve of the space suit and wiggled her fingers into the outer glove.

Time to get out of here.

She opened the decon-shower air-lock door, stepped into the air lock, closed the door, and latched it. She pulled the shower chain, and a spray of chemicals hissed down over her space suit. While she was taking the chemical shower, she realized that she did seem to have a low-grade fever. Oh, this is great, she thought. I already don’t feel well, and now they’re going to take my temperature and then lock me up. She racked her brain trying to remember what she had been doing with her hand. Her glove had been slippery and wet… wet with detergent. Some detergents kill Ebola particles. So if there had been Ebola on her glove, maybe the detergent neutralized it. The shower stopped, and she opened the exit door and went out into a Level 3 staging area and pulled off her space suit.

The staging area is a gray room — in between the hot side and the cold side. It has lots of equipment in it, and along one wall there is a row of hooks that hold blue suits belonging to all the scientists who work in the suite. A laboratory technician, Joan Geisbert, was working in the gray area. Geisbert is a slender, quiet woman with dark, wavy hair, dark eyes, and a serious, intelligent manner. She is married to Tom Geisbert, Hensley’s boss. Joan Geisbert is an expert in Level 4 laboratory work, with many years of experience. Hensley trusted her, but she thought she’d better not say anything.

This is no big deal, she told herself. She pulled off her surgical glove and washed her hands with disinfectant soap.

She needed to know if there was a hole in her inner latex glove. That was a serious question. If there was a hole in the glove and there was bleeding on her hand, then there was a chance the scissors had cut her skin. The tip of the scissors could have been contaminated with Ebola virus. Washing her hands would do no good if a particle or two of Ebola had made it into her bloodstream.

Joan Geisbert was puttering with something, not paying any attention to her.

The way to test a surgical glove for a hole is to hold it under a faucet and fill it with water, like a water balloon. If there’s a hole, a thread of water will squirt out. Hensley went to a sink, filled her glove with water, and held it up to see. There was nothing, no leaks… but when she squeezed the glove, drops of water oozed out of a hole in the finger.

Okay. She had cut her finger in the presence of Ebola Zaire.

“Hey, Joan? I think I screwed up.”

“Let me see.” Joan Geisbert came over to the sink and inspected her finger and the hole in the glove while Hensley told her what had happened. Geisbert glanced at her with a look of alarm.

Oh my gosh, Hensley thought.

“Get dressed and report to Ward 200. I’ll call Tom and have him meet you there.”

Ward 200 contains a Level 4 biocontainment hospital suite known as the Slammer. Someone who has been exposed to a hot agent can live there for weeks in isolation, and if they become sick they are tended by nurses and doctors wearing space suits.

Hensley took a water shower, got dressed in civilian clothes, and reported to Ward 200. By the time she arrived, Tom Geisbert was waiting for her. He was flushed and nervous. Peter Jahrling had been paged, and he had broken away from a meeting in Washington and was driving back to the Institute as fast as he could. The ward started to swarm with medical doctors, Army officers, nurses, soldiers, and lab techs. An accident investigation team formed up and examined the cut on her finger. They wanted to know what she had been doing with her hands just before she had cut her glove. They took her temperature and discovered she had a fever. She explained that she thought it was just a cold. They stuck needles in her arm and drew out many tubes of blood. She was too nervous to sit on the exam table, so she leaned against it, and then she couldn’t stop pacing around the room.

Tom Geisbert took an Army major named John Nerges aside. “Can you stay with her?” he said. “Talk to her and keep her mind off it.” John Nerges is a large, kindly man, and he was concerned about Hensley, but he joked around and kept up a patter with her.

Meanwhile, the investigation team took her latex glove into another room and studied the hole. They measured the distance between the hole and the location of her cut. Maybe the scissors had not made the hole. They held a meeting out of her hearing. She paced up and down the hallway, with Major Nerges at her side. “Can I get you a soda or anything?” he asked.

“Yes, please.”

She could see the Slammer every time she passed the doorway. There was a bed with a bio-isolation tent around it, and a dummy lying on the bed. Teams of soldiers at USAMRIID used the dummy to practice handling a contagious patient. Major Nerges came back with a Diet Pepsi. “It’s no big deal,” he said. She popped the can and noticed that a soldier had walked into the Slammer and had opened the bio-isolation tent.

He picked up the dummy carried it away on his shoulder.

Hensley turned to Major Nerges. “If it’s no big deal, why is he taking the dummy away?”

Major Nerges walked over to the grunt and swatted him lightly across the back of the head. “You idiot, she’s standing right there,” he growled.

After interviewing her for two hours, and studying the glove and her hand, the accident investigators came to the conclusion that there was a low probability that Lisa Hensley had been infected with Ebola virus. Her glove had been wet with detergent, and they felt it would most likely have killed any virus particles. She was free to go home and get some rest. However, she would need to report to an Army doctor twice a day for the next three weeks.

She wasn’t sure her mother should know about this. She went to a telephone near the Slammer and dialed her parents’ house in Chapel Hill. Unfortunately, her mother answered.

“Hi, Mom. I need to talk with Dad about science.”

In a moment, her father came to the phone, and Lisa told him what had happened.

He spent a long time calming her down. “Let’s not tell your mother. I’ll call you every day.” He was worried about her, but he said, “I think you need to suck it up and get back in there and finish your experiment.”

“I know. I know I do.”

Otherwise, she might never go back.

At six o’clock, after most people had gone home, she returned to the locker room in suite AA4, put on surgical scrubs and her space suit, and faced the steel door that led inward to Biosafety Level 4. It was a matter of turning the handle and pulling the door open. That was not difficult. The staging room was quiet, empty, with only the sound of her breath running inside her faceplate, which was starting to fog up. Through her visor she saw the red, spiky biohazard symbol on the steel door. Suck it up and turn the handle.

Peter Jahrling arrived at the Institute and went looking for Lisa Hensley. He didn’t find her in her cubicle, so he went to Tom Geisbert’s office: “Jesus, Tom, she’ll never want to go back to the lab. Was she crying? Where is she?”

“She went into AA4, Pete.”

“You’re kidding.”

The door was heavy, and it swung open slowly. She latched it behind her and stepped through the air lock to the hot side.

Up in Geisbert’s office, Jahrling was saying, “Would you and Joan mind giving her the talk?”

“What talk, Pete?”

“The one I don’t want to give her. About not sharing body fluids with anyone during the incubation period of Ebola.”

An hour later, Hensley emerged from the hot suite, chilled and shivery, feeling a little feverish and perhaps a little trembly, but she had finished the experiment.

Joan and Tom Geisbert were waiting for her on the cold side. They invited her out to dinner at a Mexican restaurant, where they bought her some dinner and two beers. The beers helped. Tom and Joan looked at each other, and Tom said to Lisa, “I’m supposed to give you the talk about not sharing body fluids with anyone for a while.”

“Yeah?”

“That was the talk.”

“You mean when I kiss a guy, no swappin’ spit?”

Tom turned red, and Joan burst out laughing.

She assured them it wasn’t an issue right then. In fact, Hensley did have a date lined up that night, a first date with a man she didn’t know very well. Finally, she phoned him and asked if he wouldn’t mind putting off the date, since she had just had a potential exposure to Ebola virus.

He was very understanding.

She drove back to her apartment, which seemed freezing cold, and so she placed a space heater on the floor by her grandmother’s couch, turned it on, lay down on the couch, and wrapped herself in a blanket. Her cat, Addy, curled up with her. Then she began calling her closest friends, and she stayed up late that night on the couch talking with them. She slept for a while, and awoke from a turmoil of blue-suit nightmares. She was boiling hot, her throat was parched, she had a fever…. Where am I? — and there was Addy, purring at her side.

Hensley continued her work with Ebola virus, somewhat oblivious to the heated arguments between smallpox experts about whether variola should live or die. The smallpox virus was a relic of the past to her, a virus with a seventies feel, like an album by Debbie Boone. She was more interested in trans-species jumps of viruses that were emerging right now.

She also had her mind on children: what was a woman scientist on a fast track supposed to do about children? She started playing volleyball in a league and met a man named Rob Tealle, who became her significant other. He was a builder and general contractor who worked around Frederick — a smart man, but not a scientist. Hensley packed her grandmother’s couch into a U-Haul trailer and moved to an apartment in Frederick. She and Tealle became very close. It was the biggest relief in the world to go home after a day in a blue suit and talk about normal things with a normal guy.

A Failure in Atlanta

After the who committee opened a three-year window in which live smallpox could be worked on, Peter Jahrling and John Huggins put together a plan to try to infect monkeys with the virus. The Food and Drug Administration has long insisted that new drugs for a human disease be tested in humans before they are licensed for use. This is not possible in the case of smallpox. Since smallpox has been eradicated, no one is infected with it, and you can’t (legally) infect people with a lethal disease just to study them. So the FDA was in a bind over smallpox. It published a draft of a new rule, the Animal Efficacy Rule, which says that for an exotic threat such as smallpox, the FDA would license a new drug or vaccine if it could be tested in two different animals that had the disease, and if the disease resembled the human disease — if there was an animal model of the disease.

Peter Jahrling wanted to get an animal model of smallpox that they could test drugs on and that the FDA would accept. Since there is no smallpox at USAMRIID, Jahrling assembled a research team and flew them to Atlanta. He got permission from CDC officials to bring the smallpox freezer out from its hiding place and allow his team to take out the smallpox, warm it up, and try to infect monkeys with it. Jahrling decided to infect the monkeys by having them breathe smallpox in the air, to mimic the way it spreads among humans.

The USAMRIID scientists built a portable aerosol chamber that they called the Monkey Cabinet. It is a huge device made of plastic and steel, and it has wheels, so it rolls. They trucked the Monkey Cabinet and a number of monkeys down to Atlanta and installed them in the CDC’s Maximum Containment Lab. Jahrling and Huggins exposed the monkeys to around two million human infectious doses of smallpox. Then Jahrling went back to Fort Detrick to attend to other business, while John Huggins remained in Atlanta, monitoring the monkeys. A few days after they’d breathed enough smallpox to take out a city, some of the monkeys got a flush across their chests, and a couple of them developed a few pimples. After a day or so, the monkeys recovered.

As the experiment was winding down, Jahrling began to feel desperate. He was afraid that D. A. Henderson would label this experiment a failure and would say “I told you so” and that it confirmed the widely held belief that animals could never be successfully infected with human smallpox. The clock was ticking. A year had passed since the WHO had extended the deadline for destroying the smallpox virus, and Jahrling needed data that looked at least vaguely promising, or the WHO might not allow him to do another experiment.

He needed someone to fly down to Atlanta, take some blood from the monkeys, and do a quick study of it right there. Maybe that would show something. He asked Joan Geisbert, but her son was graduating from high school in Frederick, and she was going to be there no matter what. Lisa Hensley could probably run the tests, but she was wrapped up in Ebola research and pretty clearly did not want to be involved with smallpox. He asked her anyway.

“Yeah, I’ll do it, sir,” she said.

Jahrling began to wonder about this. If Hensley went down to Atlanta and started working with smallpox, what would happen if she enjoyed it? What if people at the CDC were impressed with her? He told Tom Geisbert, confidentially, that he was afraid the CDC people might try to poach her. USAMRIID and the CDC had a history of strained relations. Jahrling told Hensley that he would accompany her to Atlanta.

She was annoyed, and when she was annoyed she tended to rely on Tom Geisbert for advice. She dropped by his office and asked, “Does he think I need a baby-sitter in Atlanta?” Geisbert explained Jahrling’s worry about CDC poaching.

Jahrling and Hensley flew to Atlanta at the beginning of May 2000. They sat next to each other on the government-budget AirTran flight, and Hensley was uncomfortable, not to say tongue-tied. At the CDC, they put on blue suits and entered the Maximum Containment Lab. Hensley worked all day taking blood samples from monkeys that had breathed ten million human doses of smallpox and seemed fine.

Three days later, Hensley was back at Fort Detrick with the raw data from her tests. A month later, Jahrling flew to Geneva and presented Hensley’s data to the Ad Hoc Committee on Orthopoxvirus. He argued that the data was “suggestive,” which meant that the experiment had bombed. D. A. Henderson argued that Jahrling would never be able to infect monkeys with smallpox, that it just wasn’t going to work. Jahrling pleaded for another chance, and the committee agreed to let him try again — in another year.

Then, out of nowhere, came a discovery that shook the smallpox experts to their cores.

Nuclear Pox

A few months after the failure of his monkey-model experiment, on a hot Saturday in early September 2000, Peter Jahrling flew to Montpellier, France, for the thirteenth International Poxvirus Symposium. It was held at Le Corum, a modern conference center in the middle of town. The place was jammed with more than six hundred poxvirus experts from around the world, many of them milling in the lobbies and chain-smoking cigarettes. On Sunday afternoon, Jahrling wandered around a lobby where scientists were showing poster papers.

A poster paper is much like the reports that children give in school. It’s usually about an experiment that doesn’t warrant a full presentation. A scientist makes up a poster that summarizes the experiment, hangs it up and stands next to it, and answers questions.

There were fifty or sixty poster papers hanging on bulletin boards. Jahrling bumped into Richard Moyer, an American poxvirus expert who is the chairman of the Department of Molecular Genetics at the University of Florida in Gainesville. There was a lot of noise and cigarette smoke, and they wanted to talk, so they found a poster that nobody was looking at. Jahrling and Moyer placed themselves to one side, so they wouldn’t disturb the scientist standing next to the poster, and they chatted about some of the things they’d been learning. Moyer glanced over at the poster. He stopped talking.

The experiment described on the poster had been carried out by a group of Australian government researchers from the Co-operative Research Centre for the Biological Control of Pest Animals, in Canberra. They were using viruses to try to cut down populations of mice. The scientist who led the work, Ronald J. Jackson, was the man standing beside the poster. Jackson is tall, with a roundish face, dark, short hair, and a nut-brown tan. He was a pleasant-looking man, wearing a yellow short-sleeved shirt and brown pants.

The Australian group had been working with the mousepox virus, which is closely related to smallpox. Mousepox, which is also called ectromelia, cannot infect humans and doesn’t make them sick, but it is lethal in some types of mice. The Australian group had been infecting mice with an engineered mousepox virus that was supposed to make the mice sterile. But the engineered mousepox had wiped out the mice.

The mice were naturally resistant to mousepox, and some of them had also been vaccinated. Even so, the engineered virus had sacked them. It had wiped out a hundred percent of the naturally resistant mice and sixty percent of the immunized mice.

The Australian scientists had added a single foreign gene, the mouse IL-4 gene, to natural mousepox virus. The mouse IL-4 gene produces a protein called interleukin-4, a cytokine that acts as a signal in the immune system. By putting a mouse gene into natural mousepox, the researchers had created a superlethal, vaccine-resistant pox of mice.

If a pox that crashes through a vaccine could be made for mice, then one could probably be made for men.

“My God, Peter, can you believe what these jackasses have done?” Moyer blurted.

Jahrling stared at the poster. He got the point of it right away: the Australians had engineered a poxvirus that could overwhelm the vaccine, and they’d done it by putting a single gene from the mouse into the virus. One mouse gene into the pox. Child’s play. “Holy shit,” he said.

“This virus just mowed down these immunized animals,” Moyer whispered in a low voice to Jahrling, staring at the mouse man from Australia, who was looking rather hopefully at them, like a salesman without any customers. But the two Americans drifted away. “If I were a bioterrorist, Peter, I would rip that paper down and take it home with me.” Moyer glanced back at the Australian. “Maybe that paper should come down right now. It makes me wonder if the vaccination strategy for smallpox would work,” Moyer said.

Jahrling went back to his hotel room and mentally kicked trash cans around. The poster looked to him like a blueprint for the biological equivalent of a nuclear bomb. People were attending the conference from countries that were suspected of secretly developing smallpox as a weapon, and there was no doubt that genetic engineering was something they were perfectly capable of doing. This poster might give them ideas for how to make a smallpox that could be vaccine-proof. He was especially worried about the Vector scientists. Lev Sandakhchiev was walking around, adding his blue Russian cigarette smoke to the haze in the conference center.

It was late in the afternoon, and there was a bus trip planned to the Pont du Gard, a Roman aqueduct that spans a gorge near Nîmes. Jahrling went downstairs and found Dick Moyer. They got on the bus together and sat down. Then Moyer spotted Ron Jackson sitting by himself near the back of the bus. “See you later,” Moyer said, and he hurried down the aisle and claimed the seat next to Jackson.

“That paper of yours is one of the best papers at the meeting,” he said, trying to break the ice.

The bus wound through the beautiful terrain of Languedoc, through olive groves and past limestone cliffs. Moyer found Jackson to be a “nice guy, kind of a shy guy, and a good scientist.” They had a talk about how, exactly, the engineered pox had wiped out the immune mice. Moyer was very interested in the exact way in which a poxvirus could trigger a storm in the immune system and overwhelm the vaccine. “Ron Jackson and his group knew what they had done,” he said later. “Anybody working in this field would have to be absolutely retarded not to see the implications of it with the vaccine for smallpox. They’re professionals, and they saw it. They agonized over publishing their experiment. But I still can’t believe they published it.” A vaccine-resistant smallpox would be everyone’s worst nightmare come true. We could be left trying to fight a genetically engineered virus with a vaccine that had been invented in 1796.

The Australian researchers were working for the government, and they had asked officials what they should do. Information travels fast via the Internet. Word could leak out about their experiment, even if they didn’t publish it. Putting the IL-4 gene into a poxvirus was such simple work that a grad student or summer intern could probably do it. Virus engineering had become standardized, and there were kits you could order in the mail for doing it. It was getting easier to alter the genes of a virus all the time, and poxviruses were just about the easiest viruses to engineer in the laboratory.

Ron Jackson and his colleagues — principally, a molecular biologist named Ian Ramshaw, who had done the technical work of constructing the virus — talked it over with one of the leading eradicators of smallpox, the Australian pox virologist Frank Fenner. Fenner had done some of the early and important research on mousepox virus, and he is the principal author of the Big Red Book—Smallpox and Its Eradication. He advised them to publish. He felt that there were reasons to think that IL-4 smallpox — smallpox with the human IL-4 gene spliced into it — might not work the same way as IL-4 mousepox did in mice. Furthermore, he felt that an engineered smallpox that did spread through vaccinated humans would not be useful as a biological weapon because it would kill too many people too fast, and so would not spread well, in his opinion, and it might kill the people who made it. Fenner also believed that a terror group or a nation would need to test the engineered smallpox on human subjects in order to be sure it worked. That was a difficult hurdle, he reasoned.

As for Jackson and Ramshaw, one impulse for publishing their work seems to have been simply to remind the world that the genetic engineering of virus weapons was something quite possible. They wanted to warn the community of biologists to stop pretending the problem didn’t exist, and to start discussing it and dealing with it.

The Jackson-Ramshaw paper was published, with a small burst of publicity and media attention, in the Journal of Virology in February 2001. At that point, the technique for engineering a presumably vaccine-resistant super mousepox became available worldwide on the Internet.

The Jackson-Ramshaw experiment provoked an uneasy reaction in the American intelligence community. CIA biologists were apparently aware of the paper, since it pointed to a vulnerability in the government’s plans to assemble a stockpile of vaccine. The paper was discussed at the National Security Council. One member of the NSC believed that the Australian scientists had intentionally published their experiment out of scientific pride. This was an unreasonably cynical view of Australian scientists, but it reflected the unease with which the intelligence community viewed the possibilities for genetic engineering of virus weapons.

After giving a couple of interviews with journalists, Jackson and his group decided to let others do the talking for them. Dr. Annabelle Duncan, an Australian government scientist, argued that the researchers had done nothing wrong and that unexpected findings are a normal part of science. “I got especially rabid e-mail from people in the United States,” she said. “But it would have been silly and dangerous not to publish the paper, because there would have been an implication that we were doing something harmful.” She maintained that the group had been surprised by the result and had never thought the immunized mice would die, and this seems true. In essence, the Jackson-Ramshaw team had had a laboratory accident with an engineered virus and had chosen to tell the world what had happened.

A month later, officials at the CDC gave the U.S. Army permission to try a second experiment to see if, somehow, they could create a monkey model of smallpox. Peter Jahrling put Lisa Hensley in charge of the experiment.

A Slight Argument

At eight o’clock in the evening, Peter Jahrling was in his living room, packing a battered suitcase. The sun had set, but the birds were still singing, and the sky glowed with spring. Jahrling had to catch a flight to Atlanta. The Jahrlings’ master bedroom is small, and his wife, Daria, had told her husband that she did not want him packing there. “That suitcase of yours has been God knows where, like Siberia. You drag it down streets where dogs walk,” she said. “I don’t want that thing on our bed.”

So he was packing the suitcase on the rug in front of the television set, which was on, although nobody was watching it. Daria was gathering the children’s laundry from their rooms, walking briskly around the house with a plastic laundry basket. Their five-year-old daughter, Kira, was rolling on the couch in a bunny suit, drawing on a piece of paper with a crayon.

Daria paused briefly, holding the laundry basket. “Peter, how long are you going to be gone this time?” She is a casual person with an honest way about her. She teaches English at a local high school: Shakespeare and T. S. Eliot and the Imagist poets.

“It depends on how it goes,” he answered. He added a T-shirt and shorts.

“I thought you didn’t go into the space-suit lab anymore. Don’t you have people who can do the work for you?”

He added a light blue polyester sport coat to the suitcase. “Frankly, I’m the only one who has the passion to make it all come together right.”

Daria carried the laundry downstairs and started the washing machine. Peter was immune to everything — he had been vaccinated for anthrax and smallpox — but she and the kids weren’t. She had told her sister that she wished they all had some of Peter’s blood in them. She went back upstairs.

Kira hopped off the couch and ran over to her father, holding her paper. “Daddy, I need a clipboard.”

He went into his office and got a clipboard. She hung a picture on it and showed it to him.

“Hey, that’s nice, Kira.”

“Go brush your teeth, baby,” Daria said to Kira. Kira buzzed off to the bathroom.

“I’m going to miss her.”

“You never see her. You usually don’t get back from work until she’s in bed.”

“All I can say is, there are reasons for coming up with countermeasures to smallpox. We all know that crazies exist.”

A lot of their communication was nonverbal. She gave him a smile that was a mixture of impatience, annoyance, and wry amusement, a look they knew meant, You live in Peter’s world.

He tucked Kira in bed and read her a story and arrived in Atlanta at midnight.

Chaos in Level 4

The monkey-model team stayed at a hotel in the suburbs, not far from the CDC. At sunrise they were drinking coffee and eating bagels, scrambled eggs, and fruit in the hotel’s café. The monkey-model team consisted of Peter Jahrling, John Huggins, Lisa Hensley, and an Army veterinary pathologist, Lieutenant Colonel Mark Martinez. There was also an animal caretaker named James Stockman and two veterinary technicians, Joshua Shamblin and Sergeant Rafael Herrera. A separate science team, headed by a biologist named Louise Pitt, ran the Monkey Cabinet. This was big biology — expensive and complex. Everyone in the room was keyed up.

Lisa Hensley wasn’t a morning person and never ate breakfast. She bought a Diet Coke and drove with Sergeant Herrera to the CDC in a rented car. It was a cool, pleasant morning, and the sun was flashing through chinkapin trees and loblolly pines, and the air held scents of Georgia summer. They drove down a hollow and up a hill, turned in to the CDC campus, and showed their identification badges to a security guard. The badges were marked “Guest Researcher.”

They walked through a security door and crossed an open area, went through another security checkpoint, and arrived inside the Maximum Containment Lab. The MCL is a six-story building but does not seem large; it is embedded in the side of a hill, and three of its stories are partly belowground. It is attached to a larger structure known as Building 15. The MCL has a line of purplish smoked-glass windows that make the building look like an aquarium. There were television cameras and armed guards around. The variola freezer had been removed from its normal hiding place or places, and the security people had a live camera watching the freezer inside the hot zone.

CDC officials had decided that the Army people could work in a corridor of the sub-subbasement. The Army people felt they were getting a bit of a hazing, for it was clear that not everyone at the CDC was happy to have them there, working with smallpox. As an institution, the CDC was proud of the leading role it had played in the Eradication, and there were undercurrents of feeling around the CDC that it was just not right to be warming up variola and doing experiments with it.

The Army’s work area consisted of three small desks lined up in the corridor, illuminated by basement windows that looked out on the wheels of parked cars. Hensley sat down at a desk, pulled the Diet Coke from her bag, popped it open, and sipped it.

The others arrived, but there weren’t enough desks, so they stood, drinking coffee from foam cups. The animal caretakers were going to go in first, to feed the monkeys. Hensley waited for a while and then went up three flights of stairs and through another security point to an entry door that led inward to the smallpox. The MCL was divided into two separate hot zones, east and west. She pushed through a small door into MCL West and into a small locker room, where she undressed.

There was a circular scar on her upper left arm — the site of a fresh smallpox immunization. She pulled a green cotton surgical jumpsuit from a shelf and buttoned up the front. The fabric was faded and tore easily: it had been sterilized in an autoclave many times. Another shelf held athletic socks that had been sterilized and were crispy and brownish. She rummaged around for a pair that seemed less crispy. Barefoot and holding the socks, she walked through a wet shower stall and opened a door. It led to a supply closet. She walked through the closet, pushed open a door, and entered the space-suit room.

It was a Level 3 room, close to the hot side, jammed with blue space suits hanging on hooks. Each suit was marked with the name of its owner. Most of the suits belonged to CDC scientists. They had seen hard use — the seats of some of them were patched with black tape. (They tend to develop holes in the buttock area when you sit down.)

Her space suit was brand-new. She really liked that new-space-suit smell. She snapped on surgical gloves, taped the wrists to the sleeves of her scrubs, and carried her suit back into the supply closet, where she sat on a box and put her legs into the suit. She stood up, pulled the faceplate down over her head, and closed the front seal, which snapped shut automatically. She selected an air regulator — a steel canister with a shoulder strap. She slung it over her shoulder and plugged the regulator into her suit.

There was a stainless-steel door on the inward side of the room that had the red biohazard symbol on it. She shuffled into the air-lock decon shower, closed the outer door, opened the inner door, and stepped through to the hot side. She was in a small room where galoshes were sitting on the floor — the boot room. She stepped into a pair that looked about her size. The galoshes were to protect the feet of her suit from developing holes. Then she pushed through a swinging door into the main room of MCL West.

The main room was forty feet long, and it was in the shape of an L. The walls were covered with brilliant white tiles, and the light was bright. Red air hoses dangled in coils from the ceiling. An array of freezers stood along one wall, one of which was the smallpox freezer. Hensley started moving through the room. You didn’t exactly walk in Level 4, you shuffled. She pushed through a door into a lab room. This would be her workplace for the duration of the experiment. She stood up on tiptoes, pulled down an air hose, and plugged it into her regulator. There was a roar, her suit pressurized, and dry, cool air washed past her face. She spent the morning setting up test kits, getting ready for the awakening of variola.

On the far end of the main room there was a heavy steel door, and beyond it was the animal room, which was now crowded with people in space suits. The room contained four banks of monkey cages. The monkeys were calm, not vocalizing much, since they had been living in Level 4 for weeks, and they had grown used to being around humans wearing space suits. Each bank of cages had a plastic tent over it, to keep smallpox from spreading from one bank to another, in case any monkeys did develop smallpox. There were eight monkeys in the cages. The monkeys were crab-eating macaques from Southeast Asia. They had grayish-brown fur, pointed ears, and sharp, canine fangs. Jim Stockman, the animal caretaker, had fed them a breakfast of monkey biscuits. They had eaten some of their biscuits and had thrown others around the room. Stockman had cleaned up the mess. All the cages had brass padlocks on them — a crab-eating monkey can figure out any latch.

Mark Martinez, the veterinary pathologist, was in the monkey room, too, getting things set up. Martinez is a soft-spoken man in his forties, with brown eyes and wire-rimmed glasses. Some years earlier, he had attended Airborne school at Fort Benning, Georgia. One day, he had been walking around the base and had found a graveyard for dogs, overgrown with weeds. Among them were brass plates and slabs of stone. Each marker displayed the name of a dog, with its dates of birth and death. They had been killed in action during the Vietnam War, had been shipped home, buried, and forgotten. Martinez thought about how many of the dogs had died in combat, perhaps defending their human companions, and he had the graveyard mowed and tidied up, and he cleaned the grave markers. He felt that the dogs had died for their country.

Lisa Hensley was standing at a work counter, setting up her equipment. She was looking down at her hands, when she noticed that her right outer glove had developed a crack in the wrist. The glove was rotten.

She had no tolerance for bad gloves. Time to get out.

She picked up a bottle of Lysol, sprayed her glove, and headed for the exit. She took off her galoshes and stepped into the decon shower and pulled a handle to start the cycle.

A spray of water, then Lysol came down over her. After it ran for seven minutes, she turned a handle to shut it off. It wouldn’t turn off. It was jammed open, and the shower was still running with Lysol.

“Oh, crap,” she said. She returned to the hot side and tapped the vet tech, Josh Shamblin, on the shoulder and pointed to the air lock. “It’s running. It won’t stop.” She had to shout, since both of them were wearing earplugs inside noisy suits; it helped if you could read lips.

He said to her, “Get Jim.”

Jim Stockman had worked in MCL West before, and he knew how to fix the decon shower. He clambered into the air lock and started banging around in the spray, trying to fix the mechanism.

Peter Jahrling had arrived in the gray area with John Huggins, and they were peering at Stockman through a window in the air lock. “What the heck are you doing?” Jahrling mouthed.

“Fixing it.”

Suddenly, the floor drains in the main room began puking up nasty yellow foam. It was dirty Lysol, overflowing from the waste drains.

Rafael Herrera came running out of his workroom, lumbering in his suit, shouting, “We’ve got a flood in here!”

Hensley went over to the window of the shower and started pounding on the glass. “Jim! Jim! Look!” Mark Martinez and the others were now careening around the main room, their voices sounding dull and faint as they yelled at one another inside their suits. One of them picked up the receiver of a wall phone and called the CDC’s Level 4 janitorial services: “We’ve got a Lysol flood in here! The plumbing is backing up!”

The monkeys probably thought it was pretty exciting.

The shower stopped. Stockman opened the door of the air lock, and more Lysol poured into the room. They found a Sears shop vacuum and ran it around the hot zone to suck up the flood.

It had been a long day. The team drove back to the hotel, and most of them went straight to bed. Hensley stayed up long enough to phone Rob Tealle. She told him that everything was okay, except for a flood in the lab. He had been working on a project to build some houses. The project was winding down, and he was planning to direct his business toward furniture building. It was a brief conversation.

The Awakening

At eight o’clock the next morning, John Huggins crossed through the main room of MCL West in a blue suit, went somewhere, and retrieved the Smallpox Key. Huggins is a calm, deliberate, chunky man with a pointed nose, tortoiseshell eyeglasses, and dark, wavy hair with a splash of gray at the temples. He went to an array of freezers of various kinds, all lined up against a wall. There were chest freezers, and there were freezers that looked like kitchen refrigerators, and there were several cylindrical tanks made of stainless steel, sitting on wheels, which were liquid-nitrogen freezers. The freezers all had digital displays showing the temperature and status of the freezer.

The liquid-nitrogen freezers were shiny and new and looked a little like nuclear-reactor vessels. Each contained a shallow pool of liquid nitrogen in the bottom. One of them held the smallpox.

The freezers were chained to the wall with monstrous steel chains. Huggins shuffled up to the smallpox freezer, inserted the Smallpox Key into some sort of lock, and an alarm was disarmed, and the lock opened. There was a red panic button on the wall near the smallpox freezer. When the researchers mushed around in their space suits near the smallpox freezer, they worried that they would accidentally bump the button and draw an armed response.

Huggins slid a terry-cloth mitt over his right space-suit glove, and he lifted up the hinged circular lid of the freezer. He pushed it all the way up and back, and it clanged open. There was a whooshing sound, and a cloud of white nitrogen vapor billowed out of the top of the freezer, poured down its sides, and spread out across the floor, running around his legs. He could barely see the white cardboard boxes in the mist inside the freezer. He had about three minutes to get the vials he wanted before the pool of liquid nitrogen in the bottom of the freezer came to a boil and threw up a huge cloud of fog. The boxes were stacked one on top of another on steel racks.

He couldn’t see a thing. He reached into the fog and started feeling around. He counted down a certain number of boxes and slid a box out of a rack. He removed the lid of the box, which was still hidden from sight in the fog. The inside of the box was divided into a grid, and with his fingertips, he counted a certain number of columns across, then down a certain number of rows. He pulled five vials out of the grid. He wedged the vials into a plastic rack, lowered the lid of the freezer with a clang, and locked it.

The vials contained smallpox seeds. Each seed was a lump of frozen amplified smallpox soup the size of a pencil stub. Holding the rack of seeds in one hand, he returned the Smallpox Key to its hiding place. He then carried the seeds into another room, where he placed them in a tank full of water that was kept at 98.6 degrees Fahrenheit, the temperature of blood.

While John Huggins was warming the smallpox, the air-lock door opened, and Peter Jahrling stepped through to the hot side. He was wearing a Delta Protection space suit — not a blue suit but a Day-Glo orange one of French design. The other scientists thought Jahrling looked hip — French couture in Level 4.

Jahrling shuffled over to Huggins: “How’s it going?”

“Ready in five minutes.”

Jahrling’s heart was racing. He thought this was what a NASA launch must feel like. It seemed clear that if they failed, the WHO would not allow any more animal experiments with smallpox. And that could slow down the development of new drugs for smallpox for the foreseeable future.

He left Huggins with the smallpox and went down the hall to see what Hensley was doing in her lab. Jahrling shouted: “Are all your tubes labeled, Lisa? Are the tubes lined up in the right order? You want to be ready to go when John brings out the variola.”

“Naw, I figured I’d wait till the last minute.” She gave him a little grin.

He didn’t think it was funny. “You want to leave as little to chance as possible, Lisa.”

“Uh-huh. Yes, sir.” Give me a break, Dr. Jahrling, she thought.

Huggins plucked the seed vials out of the water. The seeds had melted to a pink, milky liquid, which shimmered with faint opalescence, like mother-of-pearl. It was the same opalescence that appears in the pus of human victims of smallpox. He held the vials in the light and tipped them gently, peering into the variola, checking to see if it had melted completely.

The strain was called the Harper. It was collected in 1951 from an infected American soldier whose name may have been Harper, and it had somehow ended up in the Japanese national collection of smallpox, under the control of Dr. Isao Arita, one of the leading eradicators. The Harper was delivered to the CDC after the Eradication. Researchers believed it was a very hot strain.

John Huggins opened the vials and sucked the Harper from them with a pipette and dribbled the liquid into four syringes. As he loaded the syringes, he got a sweaty-palmed, nervous feeling. He was loading each syringe with a billion particles, maybe three hundred million cases of variola in one syringe, enough to toast North America. It was hot material, and it made his heart race. Huggins had handled amplified seed stock of variola before — indeed, he had grown these seeds in virus cultures in the MCL during the previous few days — but no matter how many times he handled liquid seed smallpox, he could never feel calm about it. You could just feel the explosive, infective power in those syringes. He had been vaccinated many times, but the slightest needle stick from a syringe full of amplified Harper would be likely to blow through his vaccinations like a bullet through toilet paper.

After he had loaded four syringes, he loaded an additional four vials with the Harper seed liquid. He put the vials and the syringes on a tray and carried them into the animal room, walking slowly, watching where his feet were going, and holding the tray as if it had an atomic bomb on it.

The monkey room was jammed with Army scientists and technicians wearing blue suits, waiting for the arrival of the Harper. They were hooked up to the air lines that coiled down from the ceiling. The monkeys were vocalizing, and eeks and calls sounded in the room. In the upper left cage of the first bank, a large male crab-eating macaque, Monkey C099, was watching the people. He was an alert animal, calmer and more inquisitive than the others.

Stockman and Martinez had taken note of the monkey. They had many years of experience with animals, and they were aware of differing “characters” among them. Monkey C099 had a pale muzzle with pinkish-white skin that was free of facial hair, which was unusual for a crab eater. It gave him a more human appearance than some of the other monkeys. He was a leader type, more confident of himself, and one of the largest males in the group. He had big, sharp, canine teeth. He was not a monkey to mess with.

Stockman freed some latches on Monkey C099’s cage and pulled a squeeze panel forward, which moved him toward the front of the cage. Stockman worked slowly and very gently, trying not to upset the monkey. While Stockman kept the monkey pressed against the front of the cage, Josh Shamblin took a syringe and gave the animal a shot of an anesthetic, Telazol, in the thigh.

They waited a few minutes. Monkey C099 settled down, and he almost went to sleep. Then Shamblin unlocked the brass padlock and lifted the animal out, holding it under the arms. He shuffled across the room, carrying the monkey in front of him.

Meanwhile, Huggins gave some vials of smallpox to Louise Pitt, who was in charge of the Monkey Cabinet. She loaded the liquid into a device that would make a mist inside the aerosol cabinet. Shamblin handed the monkey to Pitt, and she placed him on a table inside the chamber, lying on his back.

Then Pitt gave the thumbs-up, and one of her team started a blower running. Harper smallpox was blown into the air around the monkey’s head. The monkey breathed one hundred million particles of Harper. The monkey yawned, exposing his fangs. He was loopy with the anesthetic.

The monkey was also due to get a load of smallpox straight into the bloodstream. Shamblin took an IV needle and inserted it into a vein in the monkey’s thigh. He attached a tube to it, and he took up one of the syringes full of Harper, uncapped it, and very carefully fitted the syringe into the tube. He injected the monkey with around one billion infective particles of Harper smallpox. There was a pause. Josh Shamblin glanced around, catching people’s eyes to make sure that he had the attention of the room. The roaring of air in people’s suits was too loud for speech. He was letting everyone know that he was about to pull the contaminated needle out of the animal.

Everyone stopped what they were doing and froze, and some people stepped backward. When he was sure the room was under control, Shamblin pulled the needle from the monkey’s thigh. The steel glinted, slick with monkey blood, and every human eye in the room watched it. It was perhaps the dirtiest needle in the history of variola’s entanglement with the human species. Without capping it — he wasn’t going to get his fingers anywhere near that bloody point — he took two steps across the room and dropped it in a biohazard container. The biohazard waste containers were cooked in autoclaves inside the Maximum Containment Lab, and only after they had been sterilized were they removed from Level 4.

Then they carried the big, sleepy, pale-faced monkey back to his cage, and they repeated the process three more times with three more monkeys.

The next day, they inoculated four more monkeys with a different strain of smallpox, the Dumbell 7124, which the researchers usually called the India strain. It had been collected in 1964 in Vellore, in southern India, by a British smallpox researcher named Keith Dumbell. Three years later, in Vopal, India, Soviet scientists collected the strain known as India-1, which became their strategic-weapon strain. The Russian government has refused to share the India-1 strain with anyone, but Jahrling and his group believed that their India might be similar to the Russian India-1. They regarded it as the hottest smallpox that anyone outside Russia could obtain.

This test was different from Jahrling’s previous experiment, when his group had failed to infect monkeys with smallpox. They had used a lower dose then, and they had given the virus to the monkeys through the air. This time they also put it into the bloodstreams of the monkeys, and they used a higher dose. Jahrling felt that if a billion particles of smallpox didn’t give a monkey a disease of some sort, then nature would be telling us that variola was not going to go into any species except man.

They kept the monkeys under observation, wondering what would happen. The Harper and the India might start multiplying in the monkeys or it might not. If the monkeys became sick, no one knew what the disease would look like. It was impossible to say what variola would do.