The last thing that sounded in Richard Duvall's ears as he left the office of Monsieur Lefevre, Prefect of Police of Paris, were the latter's words, spoken in a voice of mingled confidence and alarm, "The fortunes of a nation may depend upon your faithfulness. Go, and God be with you." He entered the automobile which was drawn up alongside the curb, and accompanied by Vernet, one of the Prefect's assistants, was soon threading the torrent of traffic which pours through the Rue de Rivoli.