Horrible Harry makes second grade really exciting. But, as Doug knows, being his best friend isn't always easy. Harry loves to do horrible things, like showing Song Lee his pet snake and making her scream, or pinning Sidney to the ground and making him say "I love girls". Twice.
Yet nobody can wait to see what Harry will be for Hallowen, or what part he'll have in the school play. Even their teacher, Miss Mackle, is shocked when she finds out - because with Harry, you never know what is going to happen next!