A man enveloped in a handsome grey cloak groped through a dark alley which led into the fashionable district of the Rue de B thisy. From time to time he paused, with a hand to his ear, as if listening. Satisfied that the alley was deserted save for his own presence, he would proceed, hugging the walls. The cobbles were icy, and scarce a moment passed in which he did not have to struggle to maintain his balance. The door of a low tavern opened suddenly,...