“We can’t prove it yet, you see,” said Ellery. “But we’ve made a really good beginning on the job of bringing last Tuesday’s business home to Woodman, and we mustn’t lose any time in following up that trail to the end.” “But how do you propose to follow it up? Haven’t you done all you can there?” “No. Don’t you see? We must prove that the man the servants took for George that night when he went out of this house was really Carter Woodman.” “That all sounds very well; but I don’t see how you’re going to do it.” “Neither do I; but I mean to have a shot.” “My dear Bob, let me try. It’s my turn to do something. I have an idea, and I may be able to find out about it.” “You’re very mysterious. Won’t you tell me what the idea is?” “No, Bob. It may come to nothing; and I’d rather try it myself first. It won’t take long to find out. You’ve done all the clever things so far; and I think it’s my turn for a change.” “Right you are, Joan. I only hope it’s a good ’un.” “I hope it is; but it’s only a chance. You come back here to-night and I’ll tell you. Besides, I want an excuse for seeing you again.” “Darling,” said Ellery, and their conversation for the next few minutes can be left to the experienced imagination of the reader. Chapter XXXI A Button in a Bag As soon as Ellery had gone, Joan put on her things and walked across to the Cunningham Hotel, where she went straight upstairs to the rooms occupied by Carter Woodman and his wife. As she expected, there was no one at home. Woodman was at his office, and Marian Brooklyn and Mrs. Woodman were, she knew, away for the day. Joan locked the two doors opening on the corridor, and had the suite safely to herself. It would have been awkward if any one had interrupted her, for what she did was to make a thorough search of the rooms, looking particularly at all the articles of male clothing and going very carefully through Carter Woodman’s own belongings. Her search was entirely unsuccessful, and, having replaced everything neatly so that no one would notice that it had been disturbed, she unlocked the doors and gave it up as a bad job. “So much for that little idea,” she said to herself. “I could never really have hoped to find it there.” But was that the end of her idea? As Joan finished her tidying up she began to hope that it was not. Carter Woodman had not been foolish enough to leave what she was looking for in his own rooms; but he must, she said to herself, have left it somewhere. Where then would he have left it? Where would she, if she wanted to get safely rid of a rather bulky object, so as never to hear of it again, be likely to leave it?