"And now," the Old Man in the Corner continued after a while, "we come to that sixteenth of November when the mysterious drama occurred at No. 13, Fulton Gardens. As a general rule, it seems, Mr. Jessup was in his office most evenings until seven o'clock. His clerks and showmen finished at six, but he would, almost invariably, stay on an hour longer to go through his accounts or look over his stock. On this particular evening, just before seven o'clock, he rang for the housekeeper, Mrs. Tufnell, and told her that he would be staying until quite late, and would she send him in a cup of tea and a plate of sandwiches in about an hour's time. Mrs. Tufnell owned to being rather disappointed when she had this order because her son Mark had arranged to take her and Ann to the cinema that evening, and now, of course, they could not leave until after Mr. Jessup had gone, in case he wanted anything, and he might be staying on until all hours. However, Mark stayed to supper, and after supper Mrs. Tufnell got the tea and sandwiches ready and took the tray up to Mr. Jessup herself. Mr. Jessup was then sitting at his desk with two or three big books in front of him, and Mrs. Tufnell noticed that the safe in which the cash was kept that came in after banking hours was wide open. "Mrs. Tufnell put down the tray, and was about to leave the room again when Mr. Jessup spoke to her. "'I expect Mr. Leighton back presently. Show him in here when he comes. But I don't want to see anybody else, not any of you. Understand?' "It seems that he said this in such a harsh and peremptory manner that Mrs. Tufnell was not only upset, but quite frightened. Mr. Jessup had always been very kind and considerate to his servants, and the housekeeper declared that she had never been spoken to like that before. But we all know what that sort of people are: they have no understanding, and unless you are perpetually smiling at them they turn huffy at the slightest word of impatience. Undoubtedly Mr. Jessup was both tired and worried, and no great stress was laid by the police subsequently on the fact that he had spoken harshly on this occasion. Even to you at this moment I dare say that this seems a trifling circumstance, but I mention it because to my mind it had a great deal of significance, and I think that the police were very wrong to dismiss it quite so lightly. "Well, to resume. Mr. Jessup was in his office with his books and with the safe, where he kept all the cash that came in after banking hours, open. Mrs. Tufnell saw and spoke to him at eight o'clock and he was then expecting Arthur Leighton to come to him at nine. "No one saw him alive after that.