The film centers on two monsters, the hairy James P. "Sulley" Sullivan and his one-eyed partner and best friend Mike Wazowski, who are employed at the titular energy-producing factory Monsters, Inc., which generates power by scaring human children. However, the monster world believes that the children are toxic, and when a little human girl, Boo, sneaks into the factory, she must be returned home before it is too late.