Sam is a 15-year-old boy with the power to fire burning light from his palms. He serves as the reluctant, elected mayor of Perdido Beach three months after the adult population vanished. Overwhelmed by the pressures of leadership and the impending starvation crisis, he constantly questions his own ability to govern while longing for the simple life of a normal teenager.

Caine is Sam's fraternal twin brother and the ruthless leader of the Coates Academy faction. He possesses immense telekinetic abilities. Recovering from an encounter with a malevolent entity in a desert mine shaft, Caine is ambitious and authoritarian. He plots to seize control of Perdido Beach's power plant, viewing leadership as a mechanism for dominance.

Known as "Astrid the Genius," she acts as the intellectual anchor and de facto scientist for the Perdido Beach community. She methodically documents the mutating environment of the FAYZ, trying to find logical solutions to their mounting crises. Behind her composed exterior, she carries the immense private burden of caring for her younger brother while advising Sam on how to govern.

Known throughout the FAYZ as "The Healer," Lana is a mutant with the unique ability to mend physical injuries. Burdened by the constant demands of the injured, she chooses to live alone to retain some control over her life. She struggles with the psychological weight of an inescapable, telepathic voice pulling at her mind from a nearby desert mine shaft.

Caine's sadistic lieutenant, known as "Whip Hand." He possesses a grotesque, living tentacle in place of the arm he previously lost in a fight with Sam. Drake revels in the absence of adult authority, utilizing violence and terror to enforce his will and indulge his psychopathic impulses.

An entrepreneurial teenager attempting to establish a functioning economy in the FAYZ. Recognizing that the town cannot survive on dwindling scavenged goods, he reopens the local McDonald's as a nightclub and begins organizing labor. He calculates that people need incentives to work and trades scarce resources like batteries and toilet paper for manual labor.

An older boy with no supernatural abilities who channels his insecurities into a dangerous political movement. Frightened by the mutants and the town's growing starvation, he begins organizing the "normal" children into a faction called the Human Crew. He uses derogatory slurs like "freak" and "moof" to scapegoat the powered kids for the community's problems.

Sam's most steadfast ally, serving as his driver, military leader, and practical advisor. Grounded by his past experiences with poverty, he remains calm and capable in the face of the town's starvation crisis. He provides the reliable, unwavering support that the stressed and reluctant Sam desperately needs to manage the FAYZ.

A cynical and shrewd girl with the mutant ability to measure the power levels of others. She acts as Caine's primary strategist and caretaker. Driven by a powerful instinct for self-preservation, she calculates her alliances carefully, choosing to stick by Caine to survive the dangers posed by more volatile individuals.

Astrid's five-year-old brother, who has severe autism and is entirely non-verbal, except for cryptic mutterings. Though he appears disconnected from the world around him, his mind possesses unimaginable power. He unwittingly created the FAYZ barrier to prevent a nuclear meltdown and now struggles as an ancient, dark entity attempts to connect with his extraordinary mind.

Sam's former best friend, who is seeking redemption and a sense of purpose after siding with Caine in the past. To help solve the town's starvation crisis, he pioneers a fishing operation on the beach. He struggles with his own perceived cowardice but gradually takes on practical, independent responsibilities to aid the community.

Known as "Mother Mary," she runs the day care center and is responsible for the youngest children in the FAYZ. Despite her nurturing exterior, she secretly suffers from severe anorexia and bulimia, relying on appetite suppressants to cope with the immense stress and trauma of her caregiving role amidst widespread starvation.

A quiet sixth grader who inadvertently discovers his mutant ability to alter his own density. His power is tied to his emotions; anger makes him incredibly heavy, causing him to sink through solid matter. Alienated by his sudden transformation and terrified of his own abilities, he represents the innocent children caught in the escalating conflict between "normals" and mutants.

A confident and cocky girl known as "The Breeze" due to her power of superhuman speed. She serves as an invaluable scout and messenger for Sam's faction in Perdido Beach. Having previously suffered abuse at Coates Academy under Drake, she harbors an intense, vengeful hatred for Caine's group and acts with unwavering loyalty to her friends.

A quiet, stoic, and highly observant girl with the mutant ability to suspend gravity in targeted areas. Rescued from Coates Academy, she serves as a formidable fighter and a grounding, moral force among Sam's allies. She is acutely aware of the growing social divisions in the FAYZ and acts decisively to protect the fragile peace.

A technological genius who recently defected from Caine's faction to join Sam in Perdido Beach. He has developed superhuman strength but prefers to rely on his technical skills, working to repair the town's cell phone network. He struggles with a need for intellectual validation, making him vulnerable to manipulation from his former allies.

A teenager whose newly emerging ability to generate microwave-like heat places him at the center of the town's anti-mutant conflict. When an argument with his housemate escalates, a tragic accident makes him a public target for Zil's "Human Crew," forcing him to flee into hiding to survive the ensuing mob violence.

Formerly known as Charles Merriman, he is a boy undergoing a painful physical mutation that is turning his body into living gravel. The transformation grants him immense strength and invulnerability, which he barters for beer to manage his pain and alcohol dependency. He acts as a source of brute force for the community's dangerous tasks.

A boy from Coates Academy with the mutant ability to camouflage himself, rendering him nearly invisible. He serves as Caine's spy and scout, sneaking into Perdido Beach to gather intelligence. His primary motivations are primal, driven entirely by fear of Caine and constant, intense hunger.

A girl who has lived alone in the national park since the FAYZ began. She possesses the mutant ability to enter and observe the dreams of people sleeping nearby. Driven out of the forest by starvation, her psychic abilities make her a target for Caine's faction, who wish to use her to uncover information about the malevolent entity in the mine.

An opportunistic teenager in Perdido Beach who manages his friend Orc. He acts as a broker, negotiating Orc's invulnerability to the mutant worms in exchange for daily cases of beer. Howard represents the shift toward exploitative self-interest as the community's resources dwindle.

Mary Terrafino's brother, who helps her manage the grueling daily tasks at the town's day care center. He assists with feeding and organizing the toddlers, providing essential support as his sister quietly struggles under the overwhelming psychological weight of their responsibilities.