Death in Fancy Dress: Fancy Dress Ball

This suspense murder mystery is set in the Albert Hall - on the night of nights, the Chelsea Arts Ball on New Year's Eve. In this setting of dancing and gaiety and bright lights, this story introduces among the light-hearted assembly of guests various characters in fancy dress hiding behind colorful masks who gather at the famous ball and involuntarily play their parts in a terrific drama that will keep any reader's hair standing rigidly on end.
But how may the horror and mystery of the deep night be explained away clearly enough to satisfy the demands of reason in the cold bright light of morning?