Timmy hasn’t studied for a test in Mr. Crocker’s class, so he wishes for a magical device that allows him to change places with anyone who comes in contact with it. Cosmo and Wanda are in a hurry, so they give Timmy his wish. At school, he uses this device to change places with AJ, but after that, his plan backfires. Will Timmy be able to stop Crocker from finding out about Timmy's fairies? Find out.