Lovable Sulley and his wisecracking sidekick Mike Wazowski are the top scare team at Monsters, Inc., the scream-processing factory in Monstropolis. When a little girl named Boo wanders into their world, it's the monsters who are scared silly, and it's up to Sulley and Mike to keep her out of sight and get her back home. In order to power the city, monsters have to scare children so that they scream. However, the children are toxic to the monsters, and after a child gets through, two monsters realize things may not be what they think.