Trent looked round to make sure that they were not overheard, then faced the other gravely. "There is one thing I may tell you," he said quietly, "that I don't think you know. Martin the butler caught a few words at the end of your conversation with Manderson in the orchard before you started with him in the car. He heard him say: 'If Harris is there every moment is of importance.' Now, Mr. Marlowe, you know my business here. I am sent to make inquiries, and you mustn't take offense. I want to ask you if, in the face of that sentence, you will repeat that you know nothing of what the business was." Marlowe shook his head. "I know nothing, indeed. I'm not easily offended, and your question is quite fair. What passed during that conversation I have already told the detective. Manderson plainly said to me that he could not tell me what it was all about. He simply wanted me to find Harris, tell him that he desired to know how matters stood, and bring back a letter or message from him. Harris, I was further told, might not turn up. If he did, 'every moment was of importance.' And now you know as much as I do." "That talk took place _before_ he told his wife that you were taking him for a moonlight run. Why did he conceal your errand in that way, I wonder." The young man made a gesture of helplessness. "Why? I can guess no better than you." "Why," muttered Trent as if to himself, gazing on the ground, "did he conceal it--from Mrs. Manderson?" He looked up at Marlowe. "And from Martin," the other amended coolly. "He was told the same thing." With a sudden movement of his head Trent seemed to dismiss the subject. He drew from his breast-pocket a letter-case, and thence extracted two small leaves of clean, fresh paper. "Just look at these two slips, Mr. Marlowe," he said. "Did you ever see them before? Have you any idea where they come from?" he added, as Marlowe took one in each hand and examined them curiously. "They seem to have been cut with a knife or scissors from a small diary for this year--from the October pages," Marlowe observed, looking them over on both sides. "I see no writing of any kind on them. Nobody here has any such diary so far as I know. What about them?" "There may be nothing in it," Trent said dubiously. "Any one in the house, of course, might have such a diary without your having seen it. But I didn't much expect you would be able to identify the leaves--in fact, I should have been surprised if you had." He stopped speaking as Mrs. Manderson came towards them. "My uncle thinks we should be going now," she said. "I think I will walk on with Mr. Bunner," Mr. Cupples said as he joined them. "There are certain business matters that must be disposed of as soon as possible. Will you come on with these two gentlemen, Mabel? We will wait for you before we reach the place."