In the 34th Horrible Harry book, Mary's plans for a perfect birthday party go horribly wrong--can her friends save the day? Mary is always neat and organized, while Harry is horribly messy. But even Mary's carefully planned schedule can't help when things go wrong at her own birthday party. The party is supposed to start with the kids from Room 3B taking an exciting train ride, but when their train is delayed not one . . . not...