Exposition: The characters are George Beard, Harold Hutchins, Captain underpants/Mr.Krupp, Marvin, and Dr.Diaper. The story takes place at Horwitz elementary school and in George's backyard in his tree house. Mr.Krupp and Melvin's brains were switched, so they needed something that was called, a "Combine-O-Tron 2000" to change them back.
Rising Action: George and Harold got in really big trouble by Mr.Krupp,(Which is also the principal) because they were told to study and they didn't listen.
Climax: Harold and George had a little kid hypnotize ring that had gotten taken away from Mr.Krupp and was in his drawer that was open when he went to talk to a teacher real quick. So then they went to the drawer and got the ring and then they tried to use it when he came in and it didn't work. So then he was hypnotized and he thought he was captain underpants because they got in trouble.
Falling action: They meet the world's most evilest person in the world and that is Dr.Diaper. So they have to save the world with just a little bit of time left.
Exposition: They saved the world and took Dr. Diaper down, but captain underpants takes him to the police station and put his underwear on his head. When he does that he hangs him on the pole and leaves him there, but he puts a note on him that says,"Arrest Me,"(Pilkey pg.109). When they were done with him, Mr. Krupp gets back to his regular self. An hour later he goes back into captain underpants and leaves saying,"Tralalaaaaaaaaa!"(Pilkey pg.121).