Aza Holmes is a 16-year-old high school student living in Indianapolis who struggles with
OCD, which often manifests as a fear of the
human microbiome. Constantly worried about infection, particularly by
C. diff, she repeatedly opens a never-fully-healed callus on her finger in an effort to drain out what she believes are pathogens. Throughout the book, Aza is accompanied by two close friends: Mychal Turner, an aspiring artist, and her best friend Daisy Ramirez, who writes
Star Wars fan fiction. One day at school, Daisy discovers that Russell Pickett, a billionaire construction magnate and the father of one of Aza's old friends, Davis Pickett, has gone missing in the wake of
corporate crime investigations on September 9. Russell's wife had died years prior, so Russell's disappearance leaves Davis and his younger brother Noah with no formal guardian. Tempted by the reward of $100,000 for information leading to Pickett's arrest, Daisy takes Aza on a search for the missing billionaire. After canoeing down the
White River and sneaking onto the Pickett property, they
copy a picture of Pickett that was taken shortly after the night he disappeared from Davis's
night-vision camera, and are caught by a security guard who brings them to meet Davis. To persuade the two girls to not turning in the picture to the authorities, Davis gives Aza $100,000 taken from his father's various stashes around the guest house, which she splits with Daisy. After the meeting, Davis and Aza begin dating and, at the same time, Daisy becomes romantically involved with Mychal. As time passes, Aza comes to believe that she cannot overcome her anxiety, preventing her from ever having a normal relationship with Davis. She finds numerous blog posts written by him about his feelings on both his father's disappearance and his relationship with her. Aza reads Daisy's fan fiction for the first time and discovers that Daisy has been using it as a vent for her frustrations with Aza. She continues to spiral into a
panic attack which results in her drinking
hand sanitizer and passing out. Their friendship deteriorates, culminating in a heated argument while Aza is driving on the highway that results in a car accident. Aza spends eight days in the hospital, during which she again has a panic attack, due to her fears of
C. diff, and drinks sanitizer again, this time being caught by her mother. She recovers and goes on to rekindle her friendship with Daisy. Aza also begins to improve her abilities to manage her compulsions by focusing on routine (include fulfilling her promise to Noah of help finding his father), practicing
exposure and response prevention (ERP), and taking new prescriptions. Later, at an underground art exhibition inside an unfinished drainage tunnel system off of
Pogue's Run that Russell Pickett's company was responsible for, Aza and Daisy go exploring on their own. After noticing the stench of putrefaction emanating from the area they realize that this was where Russell Pickett had run off to, and they suspect that the billionaire has already died. Aza tells Davis of their discovery, and he makes an anonymous tip to the police. The authorities locate the body, which is later reported to be that of Russell Pickett. Given the loss of their parents and home, added to the fact that their father had left his entire fortune to his pet
tuatara, Davis and Noah decide to relocate to Colorado, where they have rented a house and will be attending school. As Davis and Aza say their goodbyes, Aza reflects on the open possibilities of her future. ==Publication history==