Emmett (voiced by Chris Pratt) is an ordinary architect in the Lego world who has no sense of existence. He is energetic and optimistic every day, and carries out a day's activities according to the instructions. After work one day, he accidentally fell into a deep hole, and a strange thing stuck to his back. Then he was taken away for questioning by a policeman (voiced by Liam Neeson) who was both violent and kind. It turned out that the business king who ruled the Lego world (voiced by Will Ferrell) was extremely dissatisfied with those creative villains. He hated the intersection of different series of Lego worlds, and even more hated the unique inventions that were out of the instructions. Therefore, he separated all the worlds, imprisoned those creative masters, and planned a terrible conspiracy. Emmett was rescued by Lucy (voiced by Elizabeth Banks) at the moment of crisis, and was recognized as the savior by the prophet Vitruvius (voiced by Morgan Freeman). A storm of persecution hits the creative masters. Can Emmett, who lacks imagination, take on this responsibility?