Reef is an angry, impulsive 17-year-old boy who actively rebels against authority and uses drugs and alcohol to numb his emotions. He has lived in the foster care system since the death of his beloved grandmother, Nan, who provided his only source of comfort. Following a reckless act of vandalism that severely injures a driver, he receives a sentence to live at a group home and complete community service at a rehabilitation center. There, he struggles to adapt to strict rules and interact with the people whose suffering mirrors the damage he caused.

Leeza is a compassionate teenager who volunteers with the elderly to earn high school credit and process her grief. She recently lost her older sister, Ellen, to cancer and feels an irrational guilt over surviving. While taking a relaxing drive in her Subaru, a rock thrown from an overpass shatters her windshield, causing a massive accident. She wakes from a three-week coma with a dislocated pelvis, broken ribs, and a severe concussion, forcing her into a grueling physical and emotional recovery.

Alex is a resident at the North Hills Group Home who openly identifies as gay. He has long blond hair and an outwardly flamboyant, cheerful demeanor that intentionally provokes some of the newer, more aggressive residents. Beneath his optimistic surface, he carries physical and emotional scars from a severe suicide attempt driven by his father's hateful, anti-gay abuse.

Frank is the massive, muscular supervisor of the North Hills Group Home. As a former convict who served time in Dorchester Prison, he relates directly to the troubled youth in his care. He runs his facility based on a strict but fair contract consisting of five simple rules, aiming to provide the boys with the stable routines they lack in their personal lives.

Bigger is an enormous adolescent who uses his size to make others back down in a fight. He acts as one of Reef's primary companions in their acts of delinquency and vandalism. He is fiercely loyal to his friends but struggles to understand people outside his immediate social circle, frequently expressing prejudice.

Jink, whose real name is Stan, is a ferocious teenager missing several teeth. He earned his nickname after throwing a chair at a teacher who asked him to spell the word "Jinx." He holds a deep disdain for formal education and frequently involves himself in dangerous situations, including spending time at a local bar known as a front for illegal activity.

Scar is a highly intelligent high school student in the accelerated program and a top competitor on the school's math team. Despite rumors suggesting she works as a drug mule for her father, she consistently defends underdogs. She became friends with Reef after confidently standing up to his group of friends when they were harassing girls at soccer tryouts.

Diane is Leeza's mother, a woman worn thin by the successive tragedies in her family. Having already lost one daughter to cancer, she is horrified and enraged when Leeza suffers catastrophic injuries in the car wreck. She focuses her intense anger on the legal system and the boy responsible for the accident, demanding harsh punitive justice.

Jack is Leeza's stepfather and Diane's husband. He struggles deeply to cope with sickness and hospitals, largely because of traumas in his own family history. His inability to handle medical crises causes him to distance himself during Leeza's coma, creating significant tension in his marriage.

Ellen is Leeza's older sister who died of cancer six months prior to the novel's start. Though deceased, her memory heavily influences the surviving characters. She originally gave her sister the nickname "Leeza" because she struggled to pronounce "Elizabeth" as a child.

Brett is a small, exuberant redheaded woman recovering from severe injuries sustained when her parachute failed to open during a skydiving trip. She becomes Leeza's roommate at the rehabilitation center, bringing a vital sense of optimism and practical advice on how to mentally navigate agonizing physical pain.

Nan is Reef's deceased grandmother. She served as his primary caregiver and protector against his grandfather's abuse. She encouraged Reef's fascination with rocks and nature, often giving him "sick-stones" to hold during moments of physical or emotional distress. Her death from cancer sent Reef into the foster system.

Judge Thomas is the idealistic legal authority presiding over Reef's case. Disillusioned with the justice system's failure to rehabilitate youth, she rejects traditional incarceration in favor of sentencing Reef to a group home and community service. She demands that offenders witness the real-world consequences of their actions.

Hank Elliott is Reef's defense lawyer. He successfully advocates for Reef to receive a rehabilitative sentence rather than a punitive one, but he grows deeply exasperated with Reef's flippant, unrepentant attitude toward the legal proceedings and the victim's injuries.