In this computer animated film monsters James P. Sullivan (Sully) and his partner Mike Wazowski work for Monsters, Inc., a utility company that collects children's screams to generate energy for the city Monstropolis. One night, Sully, the top scream-generator, and Mike accidentally let a human girl through her closet door into Monstropolis. They work to return the little girl to her own world, while the CEO of Monsters, Inc. tries to capture her in order to collect more scream energy.