Estrella is a young girl living in a Mexican city that has been ravaged by the Mexican Drug War. While engaged in a fairy tale writing assignment, her classroom is suddenly interrupted by the sound of gunfire outside, creating a panic among the students. In the chaos, Estrella's teacher gives her three pieces of chalk, claiming they hold the power to grant three wishes. Shortly after this harrowing incident, school classes are suspended indefinitely.
In the streets, an orphan named Shine finds himself in a desperate situation. He steals a gun and an iPhone from Caco, a henchman working for crime boss Chino, who is actually politician Servando Esparza. Although Caco is drunkenly unaware of the theft, Shine's moment of courage falters, and he cannot bring himself to pull the trigger.
As Estrella makes her way home, she passes a corpse lying in the street, blood trailing from it right to her family's door. When she arrives, she discovers her mother is missing, likely another victim of the violence perpetrated by Chino's human trafficking ring, The Huascas. Stricken with loneliness and hunger, Estrella uses one of her wishes for her mother to return. She soon begins to have disturbing visions of her mother's ghost urging her to "bring him to us." In a twist of fate, Estrella encounters Shine rummaging through her home. She trails him back to his hideout, where she meets other orphans: Pop, Tucsi, and Morro. Despite Shine's refusal to help or accept her, Estrella chooses to stay with the group.
The plots thickens when Caco comes looking for his stolen items, leading to chaos as Morro gets kidnapped. Shine then gives Estrella the stolen gun and suggests that if she kills Caco, she can join the gang. As she sneaks into Caco's apartment, she makes a wish to avoid killing him, only to find that he is already dead. Estrella frees Morro, falsely claiming to Shine that she did the deed. Later that night, another vision of her mother warns her that the true killer of Caco will be seeking her out, instructing Estrella to deliver the man.
In a moment of despair, Estrella and her friends bring rescued boys to their rival gang leader, Brayan, where Estrella's actions spark tension, and Brayan ridicules Shine's failure to kill Caco himself. Later, Estrella finds Shine, who is crushed by the weight of his shortcomings. He confides that he keeps Caco's phone for a precious picture of his own missing mother, which was lost during a fire set by the Huascas.
As the children decorate soccer balls, Shine expresses his wish to heal his burn scars, yet Estrella cannot afford to make any more wishes due to the misfortunes they've caused. When Tio, Caco's brother, seizes Shine, the other boys use their imagination to hold a talent show to distract him. But chaos ensues as Morro intervenes, and in the ensuing confrontation, he is tragically killed by Tio.
Determined to uncover the mystery behind the phone's significance, Estrella and Shine view its contents, revealing a recording of Chino committing murder. With courage, Estrella strikes a deal to turn over the phone for Chino's promise to eliminate the remaining Huascas. Chino complies, but reveals he was behind Caco's death when the latter failed to return the stolen phone. Devastated by her realization, Estrella faces ghostly visions urging her to bring the man forth.
In a terrifying confrontation, Estrella and her friends learn of Chino’s brutality firsthand. Following a heart-wrenching burial for Morro, Estrella decides they must confront him. During their tense meeting, Estrella takes control, revealing that she still has Caco's phone and wishes for a noble cause—to rid herself and her friends of Chino's menace. However, as the situation spirals out of control, Chino discovers Shine’s deception, resulting in a tragic fate for him.
In a shocking turn of events, armed with the truth, Estrella musters the strength to face Chino in the very building where her past lives intertwine with her present. As she journeys through memories and haunting ghosts, she discovers her mother's bracelet among the victims. The culmination of this emotional spiritual journey leads her to a terrifying room full of the deceased, including her mother. In a final confrontation, Estrella uses the phone to lure Chino, sealing his fate amidst the haunting specters of his past.
Ultimately, Estrella encounters the spirit of Shine one last time, who guides her in releasing the burdens of their shared battles. As he sets the body pit ablaze, Estrella escapes into the open field, greeted by an unexpected sight: a tiger, symbolizing freedom yet another lingering shadow of her harrowing experiences.
