In Corpus Christi, Texas, Billie Jean Davy (Helen Slater) and her younger brother Binx (Christian Slater) head out for a day of fun at the lake. Their joy is short-lived, however, as a local bully named Hubie Pyatt (Barry Tubb) and his gang steal Binx's motorbike. When Billie Jean approaches the police for help, Lieutenant Ringwald (Peter Coyote) dismisses her concerns, suggesting that she simply wait two days for the bike's return.
Upon returning home, Billie Jean discovers the motorbike damaged and Binx injured after attempting to retrieve it himself. In a quest for justice, Billie Jean confronts Hubie at his father’s surf shop, delivering a bill for the damages. However, Mr. Pyatt (Richard Bradford) offers her just a fraction of the amount and makes unwanted advances towards her. Meanwhile, a frustrated Binx and their neighbor Ophelia (Martha Gehman) become increasingly anxious when Billie Jean takes too long.
In a dramatic turn of events, after Binx finds a gun while the trio tries to reclaim what is rightfully theirs, the situation escalates when Hubie arrives and his father deceives the teens, falsely accusing them of robbery. As the tension reaches a boiling point, the gun discharges accidentally, shooting Mr. Pyatt in the chest. Billie Jean, Binx, and Ophelia decide to go on the run, with their neighbor Putter (Yeardley Smith) opting to join them.
As the news of the shooting spreads, Lieutenant Ringwald realizes that he mishandled the initial complaint and takes responsibility for the ensuing chaos. The young fugitives become unexpected icons when local teenagers, seeing Billie Jean’s face on the news, approach her for autographs. Much to their surprise, they later hear that Pyatt is recovering, bringing them a sigh of relief. Billie Jean makes plans to turn themselves in, insisting that Mr. Pyatt reimburse them the full amount for the scooter repairs. Unfortunately, even after they agree to meet Ringwald, Pyatt's refusal to cooperate leads to a series of challenges.
Their journey sees Billie Jean becoming a symbol of defiance as she embraces her newfound notoriety, and her legend grows exponentially. They find shelter in what they think is an empty mansion, only to encounter Lloyd Muldaur (Keith Gordon), who welcomes them. Inspired by a movie about Joan of Arc, Billie Jean resolves to make a statement. She films a message demanding justice, claiming that "fair is fair," which resonates with supporters who rally around her cause.
As events unfold, Billie Jean’s group faces mounting pressure from both law enforcement and the media. Mr. Muldaur offers a huge ransom for his son’s safe return, but when Billie Jean aids a young boy in need, she further cements her position as a grassroots hero. Yet, their escapade turns treacherous when Billie Jean is chased by a man trying to claim the reward for her capture, and the group is forced to separate several times.
In a gripping climax, Billie Jean devises a plan to meet with Ringwald at a beachside event. Disguising themselves, the teens prepare for a final showdown with their fate, leading to some unintended consequences, including further confusion and chaos when actual snipers take aim at the wrong individual.
In a powerful confrontation with Mr. Pyatt, Billie Jean refutes his attempts to manipulate the narrative surrounding her. The dramatic culmination sees her refusing his coerced payment while publicly revealing his past assault on her, leading to a firestorm of media attention.
Ultimately, Billie Jean and Binx find themselves in snow-covered Vermont, contemplating their next move as they continue to evade their past and the law. Binx suggests an audacious plan involving a snowmobile, hinting at their relentless quest for freedom. As they drive away, the screen fades to black, leaving their fate ambiguous yet hopeful.
