The Piccadilly Puzzle

“At two o'clock in the morning during the month of August sounds of music could be heard proceeding from a brilliantly lighted house in Park Lane, where a ball was being given by the Countess of Kerstoke. True, the season was long since over, and though the greater part of London Society had migrated swallow-like to the South of Europe in search of warm weather, still there were enough people in town to justify the ball being given, and a number of celebrities were present.”