CHAPTER ONE

      PIA

      September 28, 1918

      The deadly virus stole unnoticed through the crowded cobblestone streets of Philadelphia on a sunny September day, unseen and unheard amidst the jubilant chaos of the Liberty Loan parade and the patriotic marches of John Philip Sousa. More than 200,000 men, women, and children waved American flags and jostled one another for prime viewing space along the two-mile route, while the people behind shouted encouragement over shoulders and past faces to the bands, Boy Scouts, women’s auxiliaries, marines, sailors, and soldiers in the street. Planes flew overhead, draft horses pulled eight-inch howitzers, military groups performed bayonet drills, church bells clanged, and police whistles blew; old friends hugged and shook hands, couples kissed, and children shared candy and soda. Unaware that the lethal illness had escaped the Naval Yard, the eager spectators had no idea that the local hospitals had admitted over two hundred people the previous day, or that numerous infectious disease experts had pressured the mayor to cancel the event. Not that it would have mattered. They were there to support the troops, buy war bonds, and show their patriotism during a time of war. Victory in Europe—and keeping the Huns out of America—was first and foremost on their minds.

      Many of the onlookers had heard about the flu hitting Boston and New York, but the director of laboratories at the Phipps Institute of Philadelphia had just announced he’d identified the cause of the specific influenza causing so much trouble—Pfeiffer’s bacillus—and the local newspapers said influenza posed no danger because it was as old as history and usually accompanied by foul air, fog, and plagues of insects. None of those things were happening in Philadelphia. Therefore, it stood to reason that as long as everyone did what the Board of Health advised—kept their feet dry, stayed warm, ate more onions, and kept their bowels and windows open—they’d be fine.

      But thirteen-year-old Pia Lange knew something was wrong. And not because her best friend, Finn Duffy, had told her about the dead sailors his older brother had seen outside a local pub. Not because of the posters on telephone poles and buildings that read: “When obliged to cough or sneeze, always place a handkerchief, paper napkin, or fabric of some kind before the face,” or “Cover your mouth! Influenza Is Spread by Droplets Sprayed from Nose and Mouth!”

      Pia knew something was wrong because the minute she had followed her mother—who was pushing Pia’s twin brothers in a wicker baby pram—onto the packed parade route, a sense of unease had come over her, like the thick air before a summer thunderstorm or the swirling discomfort in her belly right before she got sick. Feeling distraught in crowds was nothing new to her—she would never forget the panic she’d felt the first time she walked the busy streets of Philadelphia, or when Finn had dragged her to the maiden launch of a warship from Hog Island, where President Wilson and thirty thousand people were in attendance, and the water was filled with tugboats, steamboats, and barges decorated with American flags.

      But this was different. Something she couldn’t name seemed to push against her from all sides, something heavy and invisible and threatening. At first she thought it was the heat and the congested sidewalks, but then she recognized the familiar sinking sensation she had grown up trying to avoid, and the sudden, overwhelming awareness that something was horribly wrong. She felt like the little girl she had once been, the little girl who hid behind Mutti’s apron when company came, unable to explain why she always wanted to play alone. The little girl who didn’t want to shake hands or hug, or sit on anyone’s lap. The little girl who was grateful to be left out of kickball and jump rope, while at the same time it broke her heart.

      Looking up at the boys in worn jackets and patched trousers clambering up streetlamps to get a better view of the parade, she wished she could join them to escape the crush of the growing throng. The boys shouted and laughed and waved their newsboy caps, hanging like monkeys below giant American flags. More than anything she wanted to be like them too, carefree and unaware that anything was wrong. But that was impossible. No matter how hard she tried, she’d never be like everyone else.

      When she looked back down at the sidewalk, her mother had disappeared. She opened her mouth to shout for her, then bit her tongue. She wasn’t supposed to call her Mutti anymore—not out loud, anyway. Speaking German in public was no longer allowed. Her parents would always be Mutti and Vater in her head, no matter what the law said, but she didn’t dare draw attention by calling her that in a crowd. Standing on her tiptoes to see over shoulders and backs, she spotted the top of Mutti’s faded brown hat a few yards away and hurried to catch up to her, stopping short and moving sideways to avoid bumping into people on the way.

      Finally behind Mutti again, she wiped the sweat from her upper lip and breathed a sigh of relief. The last thing she needed was to get lost in the city. Bunching her shoulders to make herself smaller, she stayed as close to Mutti as possible, weaving and ducking to avoid the sea of bare arms and hands all around her, wishing her mother would slow down. If only she could crawl into the baby pram with her twin brothers and hide beneath their blankets. She had known coming to the parade would be difficult, but she hadn’t expected this.

      As far back as she could remember she’d been extraordinarily shy; Mutti said few people could hold her when she was a baby because she’d cry like the world was coming to an end. And she used to think being bashful was the same for everyone; that it was something you could feel, like a fever or stomachache or scratchy throat. Sometimes she wondered what would have happened if Mutti hadn’t been there to protect her from men wanting to pinch her cheeks, and little old ladies waggling their fingers at her to prove they were harmless. But gradually those feelings had changed, even more so in the last couple of months. She’d started to notice other sensations when she touched someone’s bare skin, like a dull pain in her head or chest, or a strange discomfort in an arm or leg. It didn’t happen every time, but often enough to make her wonder if something was wrong with her. Now, whenever she went to the dry goods store or vegetable market, she