Ben Crandall, portrayed by Ethan Hawke, is a bright young teen living in the suburban sprawl of Washington, D.C. His nights are filled with vivid dreams where he finds himself soaring through cotton-like clouds and gliding over an expansive, city-like circuit board, often sparked by his late-night viewings of classic 1950s sci-fi films, with The War of the Worlds (1953) being a standout favorite. Each morning, upon waking from these extraordinary dreams, Ben meticulously sketches the intricate designs of the circuit board. Eager to share his imaginative concepts, he shows them to his brilliant yet eccentric friend, Wolfgang Muller, a child prodigy whose intellect matches Ben's passion.
At school, Ben's life becomes further entangled when he develops a crush on Lori Swenson, played by Amanda Peterson. He's torn between hope and uncertainty, unsure whether his feelings are reciprocated, but nonetheless, he dives deeper into his friendship with Wolfgang and their new acquaintance, a punkish but charismatic boy named Darren Woods, portrayed by Jason Presson. The three boys band together, exploring the possibilities that lie within Ben's sketches, and it isn't long before Wolfgang brings their whimsical dreams to life; he ingeniously constructs a microchip from Ben's designs.
This ingenious chip opens up a fascinating new world for the boys, generating an electromagnetic bubble that operates without the usual constraints of inertia, allowing them to think beyond the limits of their suburban surroundings. Determined to explore the stars, they repurpose an abandoned Tilt-A-Whirl car into a makeshift spacecraft, aptly naming their vessel the Thunder Road after Bruce Springsteen's iconic song. With each experiment, they draw the attention of the U.S. government, who sends agents to investigate reports of UFO phenomena in the area.
As Ben continues to dream about the circuit board, Wolfgang stumbles upon a remarkable breakthrough—a way to produce unlimited sustainable oxygen. This discovery liberates their aspirations for longer voyages and deeper galactic exploration, prompting the boys to finalize their plans for interstellar travel. Their ambitions lead to a thrilling liftoff, even amidst interference from government agents, one of whom oddly seems to root for their success.
However, during their initial journey into space, the boys soon find themselves at the mercy of an unforeseen twist—the Thunder Road gets pulled into the beam of a much larger alien spaceship. Curiosity and a sense of adventure compel them to meet their captors, two green-skinned aliens named Wak and Neek, who possess an unusual knowledge of Earth primarily derived from old television shows. As they engage in friendly exchanges with their new alien friends, the camaraderie is abruptly interrupted by the arrival of a colossal brown extraterrestrial. It becomes clear that Wak and Neek are actually siblings who have taken their father's ship out for a joyride, having sent their dreams to the boys in a longing to connect with humans.
Faced with the unexpected arrival of their father’s larger ship, which intercepts them after a feigned pirate attack, the boys are eventually allowed to depart. Before their farewell, Wak and Neek gift the boys an amulet, described as the essence of dreams, ensuring they carry a piece of their newfound friends with them. Upon returning safely to Earth, an unexpected malfunction causes the Thunder Road to crash into a nearby lake, leaving the boys feeling defeated yet hopeful.
Just when it seems the adventure has come to an end, Ben finds himself dreaming once more—this time, envisioning a vastly intricate circuit board enriched with new possibilities. In a heartwarming twist, he is not alone; thanks to the magic of Wak and Neek's amulet, his friends Wolfgang, Darren, and Lori join him in this new dream. As they marvel at the complexity of the circuitry, Lori smiles brightly at Ben, taking his hand and hinting at further adventures that await in their imaginations.
