"Horrible Harry and his classmates all love Halloween. Everyone wears a costume to school -- even Miss Mackle! Harry's costumes get scarier and scarier each year. He's been a slithering snake, a slimy green Loch Ness Monster, and a bloody Count Dracula. So everyone in Room 3B is waiting to see what Harry will be this year -- and they're all in for a really big surprise!"--Page 4 de la couverture.