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.
Harry's interest in solving mysteries has caught the attention of his classmates in 3B, so he challenges them to discover what he has hidden in a giant, old suitcase.
Selected to join the school safety patrol squad, third-grader Mary quickly turns into a bully, and classmate Doug suspects she may be tampering with the book raffle.
"When his best friend Doug discovers his top-secret hideout, Harry enlists his friends' help to save it from being developed into an apartment building"--