Sixteen-year-old Phoebe Benson wasn't always germophobic. There was a time she didn't worry obsessively about rogue pathogens lurking on every surface, lying in wait to contaminate her. But that was before her brother Toby's premature birth left him with underdeveloped lungs. Before she got Covid and infected him, putting his already fragile life in danger. To protect Toby's health in the years that follow, Phoebe dedicates herself...