Alia is a 16-year-old Muslim girl whose family recently relocated from California to New York. She is a highly imaginative aspiring artist who draws a comic book superhero named Lia to help process her feelings of restriction and frustration. Grounded by her strict parents over a misunderstanding involving a classmate, she visits the World Trade Center on September 11, 2001, to beg her father for permission to attend a film program.

Jesse is a 16-year-old girl who feels entirely invisible within her fractured family. Raised in the shadow of her older brother's death on September 11, she uses rock climbing as an emotional escape from her parents' bitter home. Feeling disconnected and angry, she falls under the influence of a rebellious classmate and participates in anti-Muslim vandalism before a court sentence forces her to confront her prejudices.

Travis is Jesse's 19-year-old older brother who died in the terror attacks on September 11, 2001. A talented saxophone player who recently dropped out of Columbia University, he returned home under a cloud of parental disappointment. He travels to the World Trade Center on the morning of the attacks with his late grandfather's pocketknife in hand, crossing paths with Alia.

Hank is Jesse's oldest brother, who left home when Jesse was four years old. Unable to endure the volatile atmosphere generated by his father's anger over Travis's death, Hank chose to distance himself completely. He works for a charitable organization in Africa and holds crucial pieces of evidence regarding Travis's final day.

Nick is a rebellious teenager who attracts Jesse with his dark, cynical demeanor. Bearing a tattoo that says "Nothing," he channels his anger over his abusive home life into vandalism. He stokes Jesse's anti-Muslim sentiments and leads her into a hate crime before abandoning her to the police.

Adam is a newly arrived high school student who immediately impresses Jesse with his climbing skills and calm demeanor. As a practicing Muslim, he faces regular harassment from students like Nick but maintains a compassionate outlook. He models forgiveness and emotional stability for Jesse as she completes her community service.

Jesse's father owns a local rock climbing equipment store. Consumed by grief over his son Travis's death, he forbids the family from discussing him and watches news programs to fuel his intense hatred of Muslims. His emotional withdrawal causes his marriage to fracture and alienates his surviving children.

A beloved fourth-grade teacher who buries her grief by filling her schedule with community activities. Unable to tolerate her husband's constant rage and refusal to discuss their dead son, she eventually decides to separate from him. She secretly preserves an album of clippings about Travis.

Alia's father, an immigrant computer designer whose office is located high in the north tower of the World Trade Center. He is a strict but caring parent who revokes Alia's permission to attend an NYU film program after a school misunderstanding.

Alia's mother, a successful immigration attorney whose career prompted the family's move from California to Brooklyn. Imposing despite her petite stature, she frequently clashes with Alia, interpreting her daughter's rebellion as intentional disrespect. She deeply fears losing Alia after the teenager ran away from home the previous summer.

Alia's older brother, who goes by "Ricky" at his high school and allows peers to assume he is Hispanic. He avoids conflict by hiding his background and his dating life from his strict parents, advising his sister to adopt a similar low-profile strategy.

Alia's grandmother, who remained on the West Coast when the family moved to Brooklyn. She provides Alia with unconditional love and historical perspective, sharing stories about the family's flight from political violence in Indonesia to explain her parents' strictness.

Travis's late grandfather, a Vietnam veteran who helped build the World Trade Center in the 1960s and worked there for decades. His recent death following a mugging serves as the catalyst for Travis's presence in the towers on September 11.

Adam's younger sister, who wears a hijab and endures harassment from Nick. Despite the bigotry she faces, she remains composed and later extends a welcoming hand to Jesse at the Peace Center, explaining Muslim dating customs without judgment.

Mother to Adam and Sabeen. She oversees the community center where Jesse must complete her court-mandated service, treating the young girl with fairness rather than judgment.

Nick's older brother, a military veteran who lost a leg in Afghanistan. He joins Nick in spray-painting buildings and verbally harassing Muslim students at their school.

A classmate known as "Hook-Up-Hailey" who is infatuated with Nick. She participates in the group's illegal tagging and frequently directs hostility toward Jesse out of jealousy.

Jesse's best friend since sixth grade. A studious and insightful girl whose Japanese grandparents were interned during WWII, she recognizes the danger of Nick's anti-Muslim rhetoric and pushes back against Jesse's descent into bigotry.

One of Jesse's core friends, characterized by her conservative church background. She correctly identifies Nick as an inappropriate and unsafe prospect for Jesse.

Part of Jesse's trio of best girlfriends. She is a romantic who hopes for a kind boy who writes poems, expressing strong skepticism about Nick's dark demeanor.

A 22-year-old woman with a heart condition who struggles to breathe as she attempts to descend the smoke-filled stairs. Travis and Alia pause their own escape to carry her purse and assist her.

A high school teacher who initially appears as just another instructor to Jesse. He holds a deeper connection to her family, having been a close friend and bandmate of her late brother, Travis.

A survivor of the September 11 attacks who visits the community center to speak about the heroism she witnessed in the towers. She uses her survivor network to help Jesse track down individuals who may have seen Travis.