The Dementors shrieked as they broke ranks, screeching angrily as the giant knights careered through them swinging maces and swords, the huge pawns swiped pikes left and right, and a mammoth bishop skewered a Dementor on the end of his ceremonial lance, as the queen beheaded another by swinging her crown into his throat. All Harry and Hermione could do was simply watch in amazement.