Cosmo and Wanda shrink Timmy so he can complete his assignment on the microscopic universe but problems ensue when Cosmo and Wanda, who have also shrunk themselves, get eaten by Vicky. Timmy must now go inside Vicky to save his godparents but stirs up a lot of trouble in the process. To make matters worse, Vicky plans on tearing apart the house and blaming it all on Timmy to his parents.