Andy's toys are accidently donated to Sunnyside Daycare when he leaves for college, and while Buzz and the others are first excited by the prospect of kids to play with, they find that being thrown, smashed, and slobbered on is not a lot of fun.

In the world behind our closet doors monsters are lurking to collect the energy of our screams. At Monsters, Inc., James P. Sullivan (Sully) is the top scream-generator with his partner Mike Wazowski. But, there's still a scream shortage in the monster world. One night, Sully and Mike accidentally let a human girl through her closet door into Monstropolis, and pandemonium ensues. Sully and Mike work to return the little girl to her own world, while...