In Turtles All the Way Down, a young adult novel by John Green, 16-year-old Aza Holmes battles a chronic and debilitating anxiety condition as she and her best friend Daisy attempt to find the whereabouts of missing billionaire Russell Pickett. This mission begins as an attempt to claim a $100,000 reward being offered for information on Pickett, but Aza's romantic feelings for Pickett's son complicate things. Her anxiety escalates into a full-scale medical crisis. The novel explores themes of anxiety, free will, identity, and absent fathers.