Frank Walker, portrayed by George Clooney, reflects on the future, but his thoughts are interrupted by a woman’s voice that suggests he's being too pessimistic. She encourages him to recall a time when he viewed the future positively, leading Frank to reminisce about his childhood experience at the 1964 World's Fair in New York City. Young Frank, played by Thomas Robinson, excitedly enters the Hall of Inventions with a large duffle bag containing his homemade jet pack. Although Judge David Nix is unimpressed by Frank's invention—admittedly a flawed creation—a little girl named Athena sees its potential.
After giving Frank a small pin, Athena guides him past the crowd to the "It's a Small World" ride. As Frank boards a boat alone, the pin activates a hidden passage, whisking him away underneath the attraction. He finds himself on a mysterious platform, witnessing a futuristic cityscape and pursuing Athena, who beckons from a strange flying vehicle. Amidst construction robots, Frank's jet pack falls and is unexpectedly repaired, leading him to soar through the breathtaking new landscape. Upon landing, Frank's optimism fades when the woman’s voice interrupts him again, sparking thoughts of doubt.
When Frank hands over the storytelling, we meet Casey Newton, who confidently claims she's an optimist. After a brief flashback of young Casey stargazing, we shift to the present where she surreptitiously sabotages demolition work at a Cape Canaveral NASA launch pad. Despite her father, Eddie, a NASA engineer played by Tim McGraw, lamenting the loss of hope in their industry, Casey shows determination. She reminds him of a fable about two wolves—one representing light and hope, the other darkness and despair—asserting that the wolf you feed is the one that triumphs.
Following more discouraging news at school about the world's impending crises, Casey discovers a mysterious pin after getting arrested for her antics at NASA. When Casey touches the pin, she's transported to an idealistic field resembling paradise, with a futuristic city visible on the horizon. Pursuing the mystery, Casey visits Blast From The Past in Houston, Texas, but her inquiries take a bizarre turn when the store owners attempt to eliminate her with lasers.
Just in time, Athena intervenes, showcasing her time manipulation abilities and revealing her true nature as an advanced robot. After a wild escape, Athena persuades Casey to seek out Frank. During their road trip, they encounter obstacles including robotic enemies and the looming threat of Governor Nix's forces, which attempt to suppress their mission.
Ultimately, they locate Frank, who initially rebuffs Casey's pleas to return to the wondrous realm she glimpsed. Yet, as the film unfolds, he is drawn into the fight against Nix and his robotic minions. Frank’s profound insight that current media feeds can psychologically doom humanity leads to an explosive confrontation. In a climactic moment, Athena sacrifices herself to destroy Nix’s device, allowing Frank and Casey the opportunity to change the narrative.
As the story nears its conclusion, Frank decides to foster a new generation of Dreamers with fresh ideas and hope for the future—a mission personified through the distribution of unique pins. The adventure culminates with a surge of inspired individuals discovering their pins and looking towards the gleaming prospect of Tomorrowland, filled with potential and optimism.
