Vali is a 16-year-old undocumented immigrant living in a dystopian 2032 United States. Originally from Colombia, she crossed the border to California as a young child and now relies on a counterfeit identification chip to attend Morrow High School and avoid detection by the newly formed Deportation Force. Fiercely protective of her younger brother, she steps into an adult role when forced to flee her home. She is resourceful and observant, frequently using math word problems to process stressful situations.

Mami is a hardworking and resilient immigrant from Colombia who works at McAuley's dairy farm to support her children. She relies on a counterfeit ID chip that sometimes malfunctions, putting her at great personal risk. After her husband's deportation, she relocates her family to Southboro, Vermont to escape escalating immigration raids in California. She instills a profound sense of hope and determination in her children.

Ernie is Vali's eight-year-old younger brother who plays soccer and loves superheroes. Unlike his mother and sister, he was born in the United States and possesses a legitimate identification chip. Despite his legal status, he is entirely dependent on his undocumented family members. He views the world through the lens of fairy tales and comic books, giving him a persistent sense of optimism.

Malakas is a teenage undocumented immigrant from the Philippines who loves astronomy and subway trains. He fled New York after his grandmother was taken by the Deportation Force. Resourceful and intelligent, he becomes a vital part of Vali's survival group, offering both practical help and emotional support as they push toward California.

Papi is Vali and Ernie's deceased father, who brought his family from Colombia to the United States seeking safety from armed conflict. He worked on farms in California before being detained by ICE, deported, and tragically murdered before the main events of the story. His memory serves as a guiding light for Vali when she faces terrifying obstacles.

Tia Luna is Mami's sister who resides in California, having obtained legal status through marriage. She is a politically active organizer who advocates for immigrant rights. For Vali and her family, Tia Luna's home represents the ultimate destination and a symbol of safety from the increasingly oppressive United States government.

Kenna is Vali's best friend and an aspiring coder who attends Morrow High School. Born in the United States to undocumented Nigerian parents, she intimately understands the fears and pressures Vali faces. She is politically conscious and shares Vali's anxieties about the government's escalating anti-immigrant policies.

Sister Lottie is a church preschool teacher in Queens, New York, who previously knew Vali's parents in San Diego. She operates her church as an underground refuge for undocumented immigrants. She uses her position and resources to provide shelter, food, and crucial transportation connections for those fleeing the Deportation Force.

Rosa is a loving and determined mother traveling toward California with her two young children. She endures miserable conditions in the back of a smuggling truck to seek a better life for her family. When their journey is disrupted, she joins Vali's group on foot, prioritizing her children's safety above all else.

Tomas is Rosa's talkative, friendly four-year-old son. Despite the dangerous and frightening circumstances of their journey, he maintains a child's energy and desire to play. He quickly bonds with Ernie, helping to bring moments of levity to an otherwise terrifying trek.

Guadalupe is Rosa's infant daughter. She accompanies her mother and older brother on the perilous journey toward the California border, relying entirely on her mother and their fellow travelers for survival.

Given the nickname "Volcanoman" by Vali due to his large, intimidating appearance, he is an undocumented immigrant originally from Brazil. He left his home country to escape persecution for being gay, working as a dishwasher before fleeing the authorities. Though he initially appears gruff and serious, he proves to be fiercely protective of his travel companions when they face danger.

Jorge is a coyote, a smuggler paid to transport undocumented immigrants across the country. He is hired to drive Vali and the others to a halfway point in Oklahoma. He operates in a highly dangerous and illegal trade, viewing his passengers more as cargo than as vulnerable people.

BJ is the second coyote driver who is supposed to shuttle the immigrants the rest of the way to California. He operates a safe house that is anything but safe, exploiting his position of power over desperate people. He maintains corrupt relationships with local Deportation Force agents.

Ronny is an associate of the coyote driver BJ. He is hostile and impatient, complaining about the immigrants and treating them with blatant disrespect while assisting BJ in his illicit operations.

Uncle Jimi is a shopkeeper in Southboro, Vermont. His store is a familiar, comforting after-school destination for Vali and Kenna until he is targeted by the newly formed Deportation Force.

Mr. McAuley is the owner of the Vermont dairy farm where Mami works. He faces violence from the Deportation Force when they raid his property to arrest undocumented workers.

Mr. Rashid owns a nearby electronics shop in Southboro, Vermont. His sudden arrest by the Deportation Force serves as an early warning to Vali's family about the escalating danger in their town.

Ms. Kochiyama is a math teacher at Morrow High School in Vermont. Her arrest by the Deportation Force deeply unsettles her students, signaling that the authorities are targeting people within the school system.

Tony is Ernie's soccer coach, originally from Korea. His unprecedented absence from practice is one of the first signs Vali notices that the Deportation Force is actively detaining community members.

Pete is Ernie's childhood friend and soccer teammate in Vermont. He represents the normal, carefree life that Ernie is forced to leave behind.

Isabel is a student Vali meets after reaching the sanctuary state of California. Her presence reminds Vali of her best friend back in Vermont, helping her adjust to a new environment.

Kelly is a database worker in California who collects information and stories from undocumented immigrants arriving in the sanctuary state. She asks bureaucratic questions that frustrate Vali.