It's the last day of school, and Johnny and Dukey are looking forward to laying around eating ice pops. However, Johnny is informed he has to pass Mr. Teacherman's final test before that can happen. Otherwise, he'll be stuck in summer school. Naturally, he goes to Susan and Mary for help, whose plan is to go into Johnny's brain and increase his brainpower to pass. Of course, things don't go as planned.
Tropes:
- Chekhov's Gun: The ice pops Dukey brings with him on the trip to Johnny's brain. They come in handy for cooling the bruise on Johnny's brain and stopping his villainous activity.
- Exact Words: When Johnny goes villain, he targets every type of test in the city (driving, blood, eye, etc). When it seems he's run out, he then goes after his parents because their last name is Test.
- "Fantastic Voyage" Plot: A self-inflicted one at Johnny's request. His sisters and Dukey go into his brain to increase his brainpower to help him pass his test. They run into trouble with a head cold Johnny has, as well as his white blood cells protecting his body. They also bump into parts of his brain that control his inhibitions, causing him to act recklessly the first time without regard for his safety and become a villain the second time.
- Running Gag: Johnny thinking a cloth the girls have is a cape, only to be told it's a table cloth. He uses it as a cape when he goes villain.
- Temporarily a Villain: When Susan accidentally slams their ship into a part of Johnny's brain, this causes him to lose his moral inhibitions and makes him want to destroy all forms of tests, donning a villain outfit to do so.
- Throw the Dog a Bone: The only reason Johnny gets a C with his score is because he destroyed a difficult test Teacherman had to take afterwards.
