In a dystopian future devastated by the Idiopathic Adolescent Acute Neurodegeneration plague, around 90% of American youths fall victim to its horrendous effects. However, the remaining children exhibit remarkable abilities, classified into distinct colors: Green for enhanced intelligence, Blue for telekinesis, Yellow for electrical manipulation, Red for fire control, and Orange for both telepathy and mind control. Among these, the Red and Orange children present such a threat that they are ruthlessly exterminated, while the others are confined to camps, living lives stripped of their former joys.
Ruby Daly, portrayed by Amandla Stenberg, is a mysterious Orange who has spent six long years in one such camp. Her sharp instincts allow her to deceive the attending doctor into believing she is merely a Green, thus ensuring her temporary safety. Ruby's life takes a significant turn when the Children's League, an underground resistance group, helps her escape. A compassionate camp worker, Cate (played by Mandy Moore), gives Ruby a panic button, which serves as a tracker in case she finds herself in danger again.
As Ruby embarks on her new journey, she becomes increasingly entwined with Rob, another member of the League. Their telepathic connection strains under Ruby's potent Orange powers, and her discomfort leads her to distance herself from the League. Together with Zu (played by Miya Cech), a mute Yellow who offers support, they eventually join forces with Liam (portrayed by Harris Dickinson) and Chubs (played by Skylan Brooks). The quartet seeks out “East River,” a mythical safe haven reputedly led by the enigmatic Slip Kid, an Orange.
Their quest takes them through an eerie, deserted mall, where they encounter a handful of others who possess information about East River. However, these strangers only drop cryptic hints, mentioning the letters "E.D.O.". With Ruby's Orange powers subtly nudging their thoughts, and with Chubs' analytical brilliance, they eventually decode the mystery, revealing radio coordinates directing them to Lake Prince, Virginia.
As they approach their goal, the group astonishes Ruby with a revelation: they plan to take her back to her childhood home in Salem, Virginia, a place intertwined with her lost memories of her parents. Upon catching a glimpse of her parents through a glass door, Ruby realizes with horror that she has unintentionally erased their memories of her, sending her into a panic. Liam's gentle nature offers comfort, yet their evolving romance faces a barrier as Ruby fears the devastation her Orange powers can unleash.
A cunning ambush led by Lady Jane (played by Gwendoline Christie) captures both Chubs and Zu, prompting Ruby and Liam to make a desperate escape. Ruby's powers are finally on display, rendering Lady Jane's attempts to thwart them ineffective. They abandon their vehicle, continuing their arduous journey on foot until they finally arrive at East River.
As Ruby's bond with East River deepens, a startling truth comes to light: Slip Kid is actually Clancy Gray, the son of the president (Patrick Gibson). As he mentors Ruby in mastering her abilities, it becomes apparent that he is leveraging this relationship to manipulate her into assisting him with memory erasure—his goal is to make her a mere puppet in his larger scheme for control.
As tensions mount, Clancy's nefarious plans become evident: he has been surreptitiously wielding his powers to influence government actions from the shadows. Shocked and betrayed, Ruby finds herself ensnared in a tangled web of deceit. With the fate of her friends at stake, she mustamer up the strength to break free from Clancy's hold and escape, fueled by the support of Chubs.
The fallout from her escape is catastrophic: Liam vacates Haven with its children, while Ruby confronts Clancy in an explosive finale that devastates East River. As she navigates her way out of the camp, Chubs begins to deteriorate, compelling Ruby to call upon the League for assistance. The organization promptly intervenes, ensuring Chubs is taken to the hospital while providing a sanctuary for Zu.
Ruby, determined to secure Liam's safety, strikes a deal to assume his role as a soldier within the League—this comes at the price of erasing his memories of her through a bittersweet farewell. Now left with the prospect of rigorous training alongside other empowered youths in the League, Ruby forges ahead, paving a new path amid the ruins of her old life.
Meanwhile, Clancy, now more entrenched than ever, surveys the landscape as his influence over the US military and governmental structures only grows stronger.
