The eccentric and childish Pee-wee Herman embarks on a big adventure when his beloved bicycle is stolen. Armed with information from a fortune-teller and a relentless obsession with his prized possession, Pee-wee encounters a host of odd characters and bizarre situations as he treks across the country to recover his bike.
When Dr. Marcus Sommers realizes that he and his troubled, estranged brother David may be prone a fatal brain disease that runs in their family, he decides to make peace with his sibling, and invites him on a trip to the Rockies. There, the brothers bond over their shared enthusiasm for cycling and decide to enter a grueling bike race through the mountains. However, Marcus' health soon begins to fail, and David must compete without his brother at his side.