text: For centuries, disease has directed—and interrupted—the course of human history. In 430 BCE, during the Peloponnesian War, what is now thought to be typhoid fever passed through Libya, Ethiopia, and Egypt, eventually doing what the Spartans could not: infiltrating Athens. Two-thirds of the population died and, eventually, Athens fell. Centuries later, smallpox claimed Roman Emperor Marcus Aurelius. A century after that, a plague caused an under-attack Britain to seek help from the Saxons against the Picts and the Scots; the Saxons soon controlled the island. Then came the bacterium Yersinia pestis—the bubonic plague. In 541, when it first appeared, Romans called it the Justinian plague, after the leader who had attempted, and was to some extent succeeding at, the revival of the once-great empire. It advanced on the world, breaking out again and again until finally fizzling out in 750 CE. By then, it had caused the deaths of some fifty million people, or over one-quarter of the population, thus sparking the apocalyptic atmosphere that fuelled the rise of both Christianity and Islam.
  
  It returned again in 1347, grinding the war between France and England to a halt and decimating the Vikings. The Black Death killed roughly two hundred million people this time, more than half the world's population. It also created a labour shortage and gave peasants the leverage to end feudalism. After that, viruses entered the killing fields in a big way. The spread of smallpox first wiped out the Aztecs and continued on to kill about 90 per cent of North America's Indigenous populations. Smallpox, or the "speckled monster," both facilitated colonialism and decimated a way of life—likely deliberately. Next came cholera, more bubonic plague, the measles, yellow fever, the flu, each toppling armies, governments, empires, and sometimes helping to create new ones. But perhaps no viral outbreak is as relevant today, at least in the wider public mind, as the 1918 H1N1 flu pandemic. It killed fifty million people and prevented the Americans from striking German reparations from the Treaty of Versailles, arguably paving the way for the Second World War. On a more positive note, it also forced massive, long-lasting healthcare reform. As Pale Rider author Laura Spinney wrote in her book about the virus, "The Spanish flu resculpted human populations."
  
  The same could be said of polio and HIV. It shouldn't surprise us that, in particular, many of these viruses have proven difficult to eradicate. Some still don't have vaccines. There are many reasons for this, but at least one is that viruses are survivors. Mubareka calls them the "apex adaptors." They have proliferated in impossible places, such as polar ice caps, salt marshes, and acid lakes. It's what first drew her to the infectious diseases field: the unpredictable interconnectedness of it all. Human behaviour and advancement, especially travel, has allowed for sickness that might once have been contained to go anywhere, everywhere. Viruses can't move on their own; they need to hitch a ride on us. Humans, in turn, created unfettered access to, well, everything, and now it's spilling over, which makes the work Mubareka does in her Toronto lab relevant on a global scale. But it's more than that. Only a small percentage of viruses borne by animals will successfully infect a person or an entire population, creating what's called a zoonosis. Some don't evolve enough to overwhelm human cells; others don't achieve high human transmission. As the virus attempts to win, it will make little adaptations here and there, mindlessly working to change its entire story. Mubareka finds it all fascinating. "A couple of amino acids and here we are," she said. "A tiny little molecular machine has effectively brought the world to its knees."
  
  ⁂
  
  [ FEEDING A COUNTRY ]
  
   "We're helping our Canadian family through this pandemic, but we don't want to go home sick."
  
  —Pramie Ramroop, meat processing plant employee
  
  Nicole Folz didn't dare go home in March 2020. Her mom had diabetes and her dad was older, edging the high-risk line of COVID-19. She didn't want to give the virus to her sister or young niece either. So, even though she felt fine and didn't know a single person who was sick, the twenty-six-year-old did what many other long-haul truckers were doing. Whenever she got back from a trip, she steered her red-and-white Freightliner Cascadia into the company's yard, parked the truck, and called it home sweet home. The lot in Guelph, Ontario, was three hours away from her actual home in Bancroft. It could have been worse. As a trucker, Folz was used to the isolation. If anyone could endure the loneliness, she figured, it was someone like her—a person drawn to long stretches of solitary driving, criss-crossing Canada and the U.S., wanderlust in her bones. Even before she became a trucker in February 2019, she used to get in her Jimmy, drive until she felt like stopping, and spend the night tucked across the seats in a grocery store parking lot. Still, it was lonely. She had also refused to see friends she'd made in the area; with all the travel she did and all the people she saw, it was just too risky. "It was kind of like I had the cooties," she said, laughing.
  
  Folz loves her job. While she jokes that she has her "womanly things to keep up with," like getting her nails and lashes done, she's always wanted to work in a traditionally male-dominated field. One of her first gigs was at a lumberyard. She went to college to learn construction drilling and blasting. She likes physical labour, likes knowing that, when a task is done, she did it justice. Plus, when you get right down to it, what she also likes is "making a man's wage." Even in such fields, though, things aren't always so clear-cut. After college, she was working road construction when she found out a kid with zero experience and who was still in high school was paid more than her. It felt like a slap in the face. The discovery helped push her into pursuing the job she really wanted. With the help of a government grant, she signed up for the required training to get the licence she viewed as freedom. She was one of the few people in her class to pass on her first try. Folz has since hauled supplies all over North America, from her Ontario headquarters to Iowa to Louisiana to Georgia.
  
  It was after a pickup in Chicago to get medical supplies, including gloves, masks, gowns, and hand sanitizer, that Folz started to feel unwell. She continued to drive down to South Carolina, playing a denial game the whole time. It's probably just a cold, she told herself. It was April 7. Chicago had been in the news as an emerging COVID-19 hotspot, and Folz, who listened to the news sometimes as she drove, knew it. Even as she tried to tell herself not to worry, that thought stuck in her head. Then again, she was only tired and a bit foggy; it could just be a cold. She reassured herself over and over and over. But she wasn't about to gamble with someone else's health. She constantly sanitized her hands and everything she touched, and wore a face mask and gloves when she did the next delivery. Pretty soon, her throat felt like a thousand bees had swarmed it. Raw and sore, she started coughing. After she walked into a building, it felt like she had run a mile to get there. She was hot, too, burning up—then again, she was in South Carolina, where it was already creeping up to 30 degrees Celsius. Maybe she wasn't used to the heat. Folz didn't have a thermometer in her truck, but she knew she needed to get one and take her temperature.
  
  In the meantime, she called her dispatcher and said, "I think I have COVID-19." It was the early afternoon, and Folz was at least a fourteen-hour drive away from her truckyard. Fatigue anchored her limbs; she needed to go back. She also needed sleep, and maybe a hospital. Instead, she had to stay the night and reload the next day. Often when she has a layover, Folz will style her hair, get dressed up, and spend a night on the town. Now, she parked her truck and curled up in the bed located behind her seat. She drifted in and out—strange, fevered dreams hunting peacefulness, rest. In the morning, she bought a thermometer. Her fever had hit 39.3 degrees Celsius. She drove through it, because what else could she do? She couldn't abandon her truck. She couldn't abandon her load. She couldn't check into a hotel and spread the virus there, even if there were room to park the Freightliner. At her stop in South Carolina, she stayed inside the cab until everybody else was gone. "Don't touch anything," she told them. "I'm sick." She felt like hell.
  
  Clutching her pink steering wheel, she felt every hour of driving as if it were six. She usually relished the open expanse of road. Now, she thought it would never end. At every rest stop, she looked at the bed behind her and cried. She'd never longed for anything so badly in her life, but it would only slow her down—and in the middle of nowhere, fever climbing. So she refused to sleep, and the closer she got to the Canada–U.S. border, the more she wondered what she should do. Could she cross? How? Where should she go once she did? How would she get there? She called her parents, who were terrified for her. And she called every public health agency she could think of, more than once, pausing every few words to gulp in air. "What protocols have been put in place?" she asked. "What's the procedure here?" Nobody seemed to know. Somebody must, she thought. There were hundreds of truckers on the road, delivering food and essential supplies. Surely, there had to be a plan if they got sick. The federal and provincial governments wouldn't just abandon them.
  
  But when Folz finally arrived at the border on Good Friday, the best option she had was a kind nurse who, during one of her numerous calls to Canadian public health agencies, had offered to let her stay in her backyard.