Planning to make a special gift for Mother's Day during art time at school, Gus the little rhinoceros is frustrated when things do not go as planned, causing him to worry that his mother will not like his gift.
Doug discovers that though being Harry's best friend in Miss Mackle's second grade class isn't always easy, as Harry likes to do horrible things, it is often a lot of fun.
Follows the school activities of second-graders, Harry and Doug, as they participate in a secret mission to celebrate "Charlotte's Web," learn how to make green slime, and put on a skit warning about the dangers of smoking.
On the last day of second grade, Song Lee's party at the local amusement park forces Harry to face his fear of elevators when he is expected to ride the Drop of Doom.
Although Froggy is very excited when his Dream Team plays for the city soccer championship, he makes a mistake on the field that almost costs the team the game.
It's almost summer vacation and the students in room 2B are having trouble concentrating on their butterfly project, until a frightening-looking new teacher comes to supervise the Suspension Room and Harry is sent there as punishment for unruly behavior.
Froggy is excited about his first sleepover, but a series of events sends Froggy and Max back and forth between their houses, until it seems they will never fall asleep.