midnight
His agent was clever . He had followed Kitty from Eightieth Street to the Knickerbocker Hotel . There he had lost her . He had loitered on the sidewalk until midnight , and was then convinced that the girl had slipped by . So he had returned to Eightieth Street ; but as late as five in the morning she had not returned . This agent had followed the banker after his visit to Kitty . He had watched the banker 's house , seen Cutty arrive and depart .