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.
"When Harry and his pals in Room 3B aren't invited to their teacher's wedding, they invite themselves, and wind up saving the day"-- Provided by publisher.
"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"-- Provided by publisher.
When Horrible Harry's pet cat, Googer, sneaks a ride and gets into the school building, third-graders Harry and Doug have to catch him before anyone else does, which means going into some forbidden places.
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.
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.
