All children know that there are monsters in their bedrooms. And at night, those monsters will come out and scare them. What children don't know is that the monsters are just doing their jobs. Monsters need to scare children and collect their screams. The monster then turns the screams into electricity for the city of Monstropolis, where the monsters live. And so starts the charming tale of Sulley, Mike and Boo and their adventures in Monsters, Inc.