Bird is an 11-year-old biracial Asian American boy living in Cambridge, Massachusetts, with his father. He formally goes by Noah, a name his father uses to keep him hidden from the scrutiny of an oppressive society, but prefers his childhood nickname. Driven by curiosity and a deep longing for his mother, he searches for clues regarding her disappearance. He often uses fairy tales to process the trauma and danger of a society that views him with suspicion simply because of his Asian heritage.

Margaret is a Chinese American poet and activist who goes into hiding after her work becomes an anthem for an anti-government movement. Once living a quiet life focused on motherhood, the criminalization of her poetry and growing anti-Asian violence forces her to leave her family. She works in secret with a network of librarians to advocate for families torn apart by the state.

Ethan is a white former linguistics professor who now works an administrative job to avoid drawing attention to his biracial son. He deeply fears the government's power and insists that Bird blend in, distancing himself entirely from his wife's legacy. Despite his cautious exterior, he retains a hidden collection of dictionaries and quietly preserves his love for language.

Sadie is a 12-year-old girl who spends years bouncing through foster care after the government forcibly removes her from her parents. Unafraid to speak up, she refuses to forget her family or assimilate into her new placements. She acts as a fellow runaway, providing Bird with critical truths about his mother's activism.

Domi is Margaret's wealthy college friend who uses her family's fortune and societal privilege to fund underground political activism. Operating under the alias 'The Duchess', she provides safe harbor, supplies, and logistical support to those fighting the government's oppressive policies. She leverages her extreme privilege as a shield for the resistance.

The public librarian is an essential node in an underground network dedicated to reuniting separated families. Having lost her own two children to medical conditions during the Crisis, she channels her grief into dangerous, covert work. She gives Bird the train schedule and specific instructions he needs to reach New York City safely.

Marie is a Black college student whose tragic death at an anti-government protest catalyzes the viral spread of Margaret's poetry. Grounded in her own family's history of slavery and forced separation, Marie protests the state's removal of children from their homes. Her use of a poetry quote on her protest sign unintentionally changes the trajectory of Margaret's life.

Mrs. Adelman is a librarian who holds deep knowledge about the families fractured by the government's new laws. After Marie's death, she meets with Margaret and exposes her to the horrifying reality of state-sanctioned child removal. She brings the grieving poet into the underground network of resistance.