If Joan Worralson,  better known to her friends as Worrals, hadn’t run into Air Commodore Raymond, Assistant Commissioner of Police at Scotland Yard, by accident in Piccadilly, the mysterious happenings on Outside Island might have remained a mystery for all time. With her friend, Betty—otherwise “Frecks” Lovell, she had just turned out of the Burlington Arcade, where they had been shopping, when they came face to face with the Air Commodore.