Ella is a high school senior carrying immense grief and guilt. Four months ago, she was the driver in a car crash on the Silver River Bridge that supposedly claimed her best friend's life, though she cannot remember the accident itself. She currently feels disconnected from her family, believing she has broken her mother's image of her as a perfect daughter. She actively avoids the swim team and hides in the school library to read her deceased friend's diary.

Sawyer is an eighteen-year-old high school student who assumes adult responsibilities to help his single mother support their family. He works hard to care for his younger brother while managing his own emotional burdens. He harbors a quick temper connected to his childhood experiences with an abusive father, but he consistently directs his protective instincts toward Ella.

Hayley is Ella's beloved best friend who died four months prior to the start of senior year after being ejected through a car windshield into a river ravine. Before the crash, she maintained a private diary where she documented her stressful home life and erratic emotions. Her written confessions reveal a young woman desperately seeking safety and validation from the men in her life.

Sam Wilkens is the school counselor at Ella's high school, known to the students as Mr. Wilkens. He leads group therapy sessions for teenagers affected by the recent car accident and takes a specific professional interest in helping Ella process her trauma. He presents himself as an empathetic figure who encourages students to vocalize their difficult emotions.

Phoebe is Hayley's mother, a woman profoundly altered by grief and a history of substance use. She relies heavily on others to manage difficult tasks, demonstrating an emotional disconnect from her parental responsibilities. She maintains a volatile dating history that created an unstable environment for her daughter.

Sean is Phoebe's unstable boyfriend who works on the electrical systems at the local YMCA where Ella lifeguards. He has a history of inappropriate behavior, including cheating on Phoebe with a younger woman and openly staring at high school girls. His presence routinely makes the young women around him feel unsafe.

Seema is a high school senior and Ella's former childhood best friend. The two drifted apart years ago when Ella became exceptionally close to Hayley. Now partnered in gym class and working together as lifeguards at the YMCA, Seema offers Ella a chance to rebuild their fractured connection.

Scott is a high school student who hosted the party on the night of the fatal car crash. He deals with his own complicated feelings about the tragedy by lashing out, frequently tormenting Ella about her role as the driver and picking fights with other students.

Callan is Sawyer's younger brother. He relies heavily on Sawyer for daily care and emotional stability, as their mother works multiple jobs to support the household. He is deeply affected by sudden conflicts in the home.

Jess is Ella's younger sister. She quietly observes the tension in her family following the car accident and attempts to act as a buffer between Ella and their highly expectant parents. She interrupts difficult moments to give her sister an escape route.