McGonagall speaks as she strides into the centre of the practice ballroom between a standing line of girls and boys.

"The yule ball has been a tradition of the tri-wizard tournament since its inception. On Christmas eve night we and our guests gather in the great hall for well mannered frivolity. As representitives of the host school I expect each and every one of you to put your best foot forward, and I mean this literally because the yule ball is first and foremost... a dance."