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.

When their teacher ends up in the hospital, the members of class 2B find a way to include her in their holiday celebration.

The students in Miss Mickle's third-grade class enjoy a boat trip on the Connecticut River after a class discussion of ancestors reveals that Sidney and Ida both have connections to the sea.

Horrible Harry, the class clown of Room 2B, returns to the spotlight with the Purple People, mysterious beings that only he can see.

When the post office has donated a real mailbox to room 3B, everyone gets jobs as sorters, stackers, and carriers. ZuZu is in charge of the misaddressed, or dead, letters. But Harry discovers that a thief is using the mailbox for something other than letters. Will he sort out what's going on? Or will Harry deliver some horribly wrong conclusions?

Horrible Harry sets out to discover who Miss Mackle is going to marry, and he takes some risky moves to be the first one to know.

Harry and his detective classmates try to find clues relating to a mysterious locked closet in Room 3B.

As Valentine's Day approaches, the students in Room 2B are preoccupied with kickball and a possible wedding between Horrible Harry and Song Lee.

Horrible Harry falls in love with Song Lee, and Harry's best friend, Doug, can't stand all that mush.

"The kids in Room 3B are asked to draw posters of things that they love, and one of them will get to share his or her poster on TV"--