nine o’clock
He had done it for Alexander when they were students together in Paris . Sunday was a cold , raw day and a fine rain fell continuously . When Alexander came back from dinner he put more wood on his fire , made himself comfortable , and settled down at his desk , where he began checking over estimate sheets . It was after nine o'clock and he was lighting a second pipe , when he thought he heard a sound at his door . He started and listened , holding the burning match in his hand ; again he heard the same sound , like a firm , light tap . He rose and crossed the room quickly . When he threw open the door he recognized the figure that shrank back into the bare , dimly lit hallway .