16-year-old Alex Lansing is tormented by his younger brother, Stevie [Spencer Breslin], whose relentless pranks push him to the edge. From buying a turkey on a pet-adoption show to orchestrating a stunt that has Harbour High jocks, Gary [Joshua Leys] and his friends, slam a pizza onto Alex’s head, Stevie’s mischief feels endless. When Alex is forced to take Stevie to the mall with his friend James [Ari Boyland], Stevie meets a kindly but quirky man, Larry Pendragon, and receives a magical coin that can grant any wish. Before Alex can intervene, Stevie darts off, leaving him to deal with disappointed parents who punish him and send him to bed early.
Stevie leaves behind the coin for Alex to mend fences, and Alex makes a reckless wish: he wishes he never had a little brother. The next morning, the world looks different. He wakes to find that his wish has come true—Stevie is gone from his old life and has become Terrence Russell McCormack, a famous child actor who stars on a TV show called Where’s Stevie? Now Alex’s life is filled with new popularity, but it comes at a cost. His former friends Abby [Lalaine] and James feel sidelined, and his new circle—headed by a popular cheerleader girlfriend, Fiona [Emma Lahana]—is shallow and demanding. The family’s career‑driven pace leaves Alex feeling lonely and longing for the smaller, more honest moments he shared with Stevie.
As Alex struggles with this alternate reality, he realizes he misses his brother and the connection they once had. He seeks out Terrence to explain that they are brothers, but Terrence rebuffs him, thinking Alex is crazy and intruding on his world. Undeterred, Alex reaches out to Abby, hoping to rekindle their old friendship, and the trio—Alex, Terrence, and Abby—form a plan to locate the magical coin again. They track down Larry Pendragon, only to learn that his shop is closed and the coin has already been sold, making their quest feel impossible.
Meanwhile, Terrence’s caretaker appears and takes Terrence away, attempting to cover up the strange disappearance. Terrence gets a call from his mother and is thrilled at first, but the call ends on a sour note when he learns his mother is getting remarried. The brothers share a heartfelt, brotherly hug before Alex slips into a deep sadness, convinced he’ll never return to his old life.
The next day brings a glimmer of hope. Alex’s father, Dave Lansing [Peter Feeney], presents him with a pile of old coins, hoping to cheer him up. In a moment of wild impulse, Alex tosses them aside until one coin catches his eye—the magic coin. When he holds it and shouts in excitement, his parents break down the door, but this is just the beginning of a new turn. Alex wishes to undo his first wish and wakes back in his own world, where he can embrace Stevie and the life they once shared. He rekindles a budding romance with Abby and, in a playful scene, tells Fiona that he isn’t her boyfriend. Later, Alex, James, and Abby take Stevie skating, teaching him the basics. Though Stevie struggles at first, the magic coin finally helps him become an astonishing skater, and the brothers’ bond is restored in the most unexpected way.
