S3·E4 The Joy
Aired June 19, 2014
Synopsis
When Miss Simian sees Gumball and Darwin joyful on Monday, she knows that something is wrong with them. She performs tests on them, but the nurse disapproves what she's doing. But suddenly, Gumball and Darwin start to infect the school with the 'Joy Virus', and it's up to Miss Simian and her tape player to cure the students.