The Master Builders were a group of Lego minifigures that were imaginative and creative and built interesting masterpieces by moving the bricks. Lord Business was confused by all the creativity deviating from his instructions, and so imprisoned any Master Builder the Super Secret Police could find in his Think Tank which is a large prison room, which saps the Master Builders's creativity and force them to make instruction booklets. Later, Emmet became a Master Builder, and helped save the other Master Builders and the other Lego citizens from certain death and was hailed as a hero by the citizens of Bricksburg.