A man enveloped in a handsome grey cloak groped through a dark alley which led into the fashionable district of the Rue de Béthisy. 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, sending a golden shaft of light across the glistening pavement and casting a brilliant patch on the opposite wall. With the light came sounds of laughter and quarreling and ringing glasses. The man laid his hand on his sword, swore softly, and stepped back out of the blinding glare. The flash of light revealed a mask which left visible only the lower half of his face. Men wearing masks were frequently subjected to embarrassing questions; and this man was determined that no one should question him to-night. He waited, hiding in the shadow.