"I have just left some of them there now," said Mrs. Pond. "I went to my room after my ride, and took off a light cloak which was fastened with three pins, each having a diamond in its head. I stuck them all into a cushion on that dressing-table." "Is the room locked?" asked Nick. "Yes," replied Mrs. Pond, and she produced the key of the door which opened from the hall above. "Will you allow me to go up there now?" "Certainly." She handed the key to Nick. He took it and walked out of the parlor. Nick had already formed a sort of working theory in the case. He scarcely believed that it would hold water, but it would do for a starter. The most probable explanation that had come to him was that Mrs. Pond had not really been robbed at all. It might be that she had some motive for making these articles vanish. Perhaps she had some need of money, and was secretly selling them against the wish of her husband and her father. So, when Nick took that key and went toward that room he did not expect to find the three diamond pins in the position described by the lady. He found the door locked, and he opened it by means of the key. Then he locked it behind him, leaving the key in the lock. He turned at once to a dressing-table. The three pins were there, just as Mrs. Pond had said. Nick laughed softly to himself. "That looks bad for my first shot at this queer case," he said; "but perhaps she didn't dare work the game while I was in the house." He glanced out of the window of the room. Two servants were in the yard. They seemed to be explaining the robberies to a new driver of a groceryman's wagon, for they had one of his arms apiece, and were pointing to the window. Nick walked into the sitting-room, and spent some minutes examining the walls, and especially the door leading toward the old part of the house. He found nothing at all to reward his search. There absolutely was no secret entrance. The detective decided that nothing further could be done in that room. He walked toward the other. To his astonishment he found that the door had been closed while he had been busy with his investigations. He sprang against it. The door yielded a little, and yet he could not open it. Some person stronger than he seemed to be holding it on the other side. He drew back for a spring. That door would have gone to splinters if it had stood in his way again. Instead, it swung open the instant he touched it, and the force of his lunge took him nearly to the middle of the room. In an instant he was on guard, but he saw no one. The room was quiet, and it was empty. The door into the hall was locked as he had left it. All was the same, except that on the dressing-table was the cushion bearing two diamond pins instead of three. The robbery had been done, as one might say, under the nose of the greatest detective in the world. "Well, this takes my breath away," said Nick to himself. "It's the nerviest challenge that ever was sprung on me."