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 to pathogen avoidance, refusing to touch any potential sources of contamination-handrails, doorknobs, vending machine buttons, and even other people-leading to an unintended life of seclusion. By the time she reaches high school, her only sources of respite are pottery class and her friendship with Walter, the elderly owner of the used bookstore where she works part-time.

Now Walter's devised a plan to help Phoebe overcome her anxiety, and she must decide whether to continue isolating herself or risk everything initiating a friendship with the charming subway busker she can't help but want to touch.