At Ralph Waldo Emerson High School, the socially awkward and bespectacled student, Barney Springboro, is deeply engaged in complex scientific experiments involving laboratory mice. This obsession frustrates his friend, yearbook photographer Peyton Nichols, who is on a quest to capture the perfect shot for an upcoming school publication. Peyton can't help but notice Barney's reluctance to mingle with others or pursue romantic interests, especially as the students gear up for a crucial baseball game against their rivals. With a cheeky tone, Peyton often pokes fun at Barney for his reclusive tendencies, while also nurturing a secret crush on the charming Corrine Updike, an administrator at the school.
When class president Bernadette insists that Peyton snap pictures of Barney with the genetically engineered orchids he’s been growing for Principal Walter Coolidge, Barney begrudgingly complies. However, a mishap occurs when he accidentally spills the feeding solution for the mice, leading to an explosion of colorful smoke that knocks him out cold. He awakens at home, where his overbearing mother gives him a stern lecture about his tardiness and antisocial comportment, as a chilling atmosphere fills the room when his bedroom door mysteriously slams shut.
The following day in English class, Barney zones out, daydreaming about the self-centered Jane Mitchell before inadvertently causing a map to tumble from the wall, striking the teacher. Meanwhile, Peyton attempts to ask Jane out, only to be met with rejection when she mentions her college-age boyfriend. A peculiar incident occurs when, while Barney is distractedly gazing at Jane, her cardigan inexplicably bursts open, leaving everyone bewildered.
In the lab, Barney starts to experiment with newfound telekinetic powers, unknowingly observed by Bernadette and Peyton. When confronted, he persuades them to keep his abilities top secret. At home, he indulges his imagination, sending model spaceships floating across the room and animating a ventriloquist dummy that frightens his mother.
The day of the pivotal baseball game arrives, and Barney’s telekinesis shines as he influences the ball, leading his team to victory with a game-winning home run. Meanwhile, Principal Coolidge tries to investigate the status of Barney's orchids but is thwarted by a locked door. Eager to document Barney's achievements for her sister's college science journal, Bernadette secures his permission, blissfully unaware of the extraordinary adventures awaiting them.
As excitement builds during pre-graduation festivities, a trio of friends—Barney, Peyton, and Bernadette—venture into an amusement park, where Peyton challenges Jane's boyfriend, Robert Wolcott, to a series of games and drinking contests. To Barney's delight, Peyton claims victory. That evening, while Peyton flirts with Jane, Barney and Bernadette share a genuine connection over dinner.
The following day, the group reunites, basking in their strengthened friendship. When they return to Barney’s lab, passions ignite, though Peyton's actions create unexpected ramifications. Jane later reveals her regret and swiftly reconciles with Robert.
Meanwhile, a subplot unfolds as Mrs. Updike masterminds a plan involving Principal Coolidge and a provocative personal ad. Their long-brewing chemistry culminates under a table in a moment of abandon.
At a fraternity party, Peyton seeks to manipulate a roulette wheel, but Barney’s attempt to intervene is thwarted when Robert activates a hidden button. In desperation, Barney causes the entire wheel to levitate, inducing chaos among the attendees.
In the aftermath of the party debacle, Barney finds himself emotionally distraught, and his once-reliable phone skills become futile. Drowning his sorrows in whiskey, he wakes with regrets, eventually mending things with Bernadette and solidifying plans for prom.
However, an unexpected twist occurs when Mrs. Springboro decides to hire two priests for an exorcism, forcing Barney to plot an escape. With his trusty ventriloquist dummy in tow, he cleverly evades the exorcists, carving a clear path to prom—and possibly a chance to reconnect with Bernadette.
As the night unfolds, Peyton and Jane are crowned prom king and queen, but Jane swiftly rebuffs Peyton's attempts at affection, revealing her insatiable quest for perfection. While Barney and Bernadette lose themselves in a shared moment of bliss on the dance floor, Peyton disrupts their joy with an impulsive offer of a trip to Las Vegas, which Barney steadfastly declines.
Tensions rise as Robert challenges Peyton over their previous roulette game, resulting in an explosive confrontation involving compromising photographs. Angered, Robert retaliates, but Barney intervenes with a powerful gust of wind, creating chaos among the students. In a dramatic culmination, Barney's telekinetic prowess reveals itself once more, as he strips Jane of her dress, leaving her humiliated.
Just when the chaos dies down, an errant fire hose knocks Barney out cold. Upon regaining consciousness, he pretends to have lost his abilities until, with Bernadette by his side, he astounds everyone by soaring through the night sky on a glittering cloud of dust, redefining the limits of possibility.
