Annabelle is a high school senior and a talented cross-country runner from Seattle, Washington. She works part-time at a bakery, volunteers at a nursing home, and excels academically with a strong interest in science. Experiencing severe post-traumatic stress disorder and intense anxiety after witnessing a violent incident nine months earlier, she spontaneously decides to run entirely across the United States. She relies on her athletic endurance and the logistical help of her family and friends to manage the physical and emotional demands of the journey.

The Taker is a new student at Annabelle’s high school who integrates into her social circle after they meet in an art class. He frequently requests rides home and displays an intense fixation on Annabelle. His behavior routinely crosses boundaries, making Annabelle uncomfortable as he ignores her firm insistence that they are strictly friends.

Grandpa Ed is Annabelle’s maternal grandfather, an Italian immigrant who moved to the United States from Gallarate at age twelve. He steps in to drive alongside Annabelle during her journey, providing food, shelter, and constant presence on the road. Deeply proud of his heritage, he frequently cooks traditional Italian dishes and maintains strong family traditions, though his stubborn nature leads to frequent clashes with his daughter.

Gina is Annabelle and Malcolm’s mother, a deeply protective woman who relies heavily on Catholic traditions and superstitions to ease her fears. She worries constantly about Annabelle's physical and mental well-being, particularly regarding her daughter's trauma diagnosis. She initially opposes the cross-country run entirely, viewing it as a reckless manifestation of trauma rather than a valid physical challenge.

Malcolm is Annabelle’s thirteen-year-old younger brother, described as a technological genius and a relentlessly optimistic presence. Despite facing bullying at school for his nerdy interests, he remains upbeat and highly proactive. He takes charge of the logistics for Annabelle's run, organizing her route and building an online fundraising presence to keep her moving.

Dawn Celeste is an older woman traveling the country in a camper with her grandson. A former feminist activist who legally changed her name at seventeen, she lives by her own rules and enjoys life on the road. She provides a safe haven for Annabelle during a bad storm and offers the teenager gentle, non-judgmental support.

Luke is Dawn Celeste’s college-aged grandson who is taking a gap year to travel the country. He shares Annabelle's love of reading and has a specific academic interest in forestry and land management. He offers Annabelle comfortable companionship during her run, carefully respecting her boundaries.

Kat is Annabelle’s best friend since sixth grade and a constant presence in her life and memories. An aspiring writer, she gifted Annabelle the Moleskine notebook carried on the journey. Brave and slightly cynical, Kat holds a permanent place at the Agnelli family dinner table.

Will is Annabelle’s boyfriend who attends a different high school and lives in a wealthier neighborhood. The son of two lawyers, he plans to pursue a career in law himself. He is smart, athletic, and well-liked by Annabelle's social circle.

Zach is one of Annabelle’s close friends from Seattle. He actively supports her cross-country journey by managing the finances and running a GoFundMe account to cover travel expenses for the RV.

Olivia is a close friend of Annabelle who takes on the role of publicist for the cross-country run. She manages social media, designs promotional materials, and schedules media interviews and speaking engagements for Annabelle in various towns.

Dr. Mann is Annabelle’s therapist in Seattle. She provides Annabelle with concrete coping mechanisms for anxiety and intrusive memories, counseling her through phone calls while Annabelle runs across the country.

Geoff is Annabelle’s friend and a teammate on the cross-country team. He hosts a significant party at his house and actively steps in to defend Annabelle when other students cross her boundaries.

Ashley is a high school student and reporter in a town along Annabelle's route. She conducts an initially awkward interview but ultimately writes a tender, inspiring article that significantly boosts public awareness of the cross-country run.