Lewis is an aspiring 12-year-old inventor at an orphanage whose inventions have been scaring off potential parents. He decides that his mother, who abandoned him at the orphanage as an infant, is the only one who ever truly loved him and works on a machine to scan his memory to locate her. Taking his memory scanner to his school’s science fair, Lewis meets 13-year-old Wilbur Robinson, a mysterious boy claiming to be a time cop from the future. Wilbur needs to recover a time machine that a man wearing a bowler hat has stolen. Lewis tries to demonstrate the scanner, but it falls apart, throwing the science fair into chaos. Upset, Lewis leaves while the Bowler Hat Guy, with the help of a robotic bowler hat named Doris, repairs and steals the scanner.
Wilbur meets Lewis at the orphanage and asks him to repair the scanner. Lewis agrees to do so only if Wilbur can prove he is telling the truth, which Wilbur does by taking them to the year 2037 in a second time machine. When they arrive, however, Lewis says he can use the time machine instead of the scanner, and he and Wilbur get into an argument and crash. Wilbur then asks Lewis to fix the time machine, but Lewis has another condition: Wilbur has to take him to visit his mother afterwards. Reluctantly, Wilbur agrees and hides Lewis in the garage. Lewis doesn’t stay there for long, however, and ends up meeting the rest of the Robinsons except for Cornelius, Wilbur’s father, who is away on a business trip. Following Lewis, the Bowler Hat Guy and Doris unsuccessfully try to kidnap him. Meanwhile, the Robinsons offer to adopt Lewis, but change their mind when they learn that he’s from the past. Wilbur admits to lying to Lewis about taking him back to see his mom, causing Lewis to run off in disgust.