"This is Mr. Barnes?" said Mr. Thauret, inquiringly, continuing at once: "Yes, of course it is. We have met twice, I think. You say your thief was dressed as one of the Forty Thieves. That interests me, for I wore one of those dresses. Why not ask all who did to allow themselves to be searched?" "I will not hear of such an indignity to my guests," at once ejaculated Mr. Van Rawlston. "Search people in my own house! No, sir. I will willingly pay for the lost gem rather than do so." "You are quite right," said the detective, keenly eying Mr. Thauret, "I am sure that it would be useless." "As you please," said Mr. Thauret, and with a satirical smile he bowed and joined the group around Miss Remsen. Mr. Barnes told Mr. Van Rawlston that it would be useless for him to remain longer, and that he would depart. He did not do so, however, until he had assured himself that Mr. Mitchel was not in the house. He went to the door, and found that the boy who had been told to guard it had been absent looking at the tableaux when the confusion occurred, so that he did not know whether any one had left the house or not. He therefore departed in disgust. "That fellow Mitchel," thought he, as he walked rapidly down the avenue,--"that fellow is an artist. To think of the audacity of waiting till the very moment when his wager would be lost, and then committing the robbery in such a manner that a hundred people will be able to testify that it occurred within the limited period. Meanwhile there is an excellent _alibi_ for him. Sick in a hotel in Philadelphia! Bah! Isn't there one man that I can depend upon?" At Forty-second Street he took the elevated road, and in twenty minutes he was at his office. Here he found the spy who had followed Mr. Mitchel to Philadelphia. "Well," said he, angrily, "what are you doing here?" "I am sure that Mitchel has returned to New York. I came on hoping to catch up with him, and at least to warn you." "Your warning comes too late. The mischief is done. Didn't you have brains enough to telegraph?" "I did just before I started." The despatch was on Mr. Barnes's desk unopened. It had arrived after he had started for the festival. "Well, well," said the detective, testily, "I suppose you have done your best. That fellow has the devil's luck. What made you think that he had come to New York? Wasn't he sick?" "I thought that might be a game for an _alibi_. To find out, I registered, asking for a room near my friend Mr. Mitchel. They gave me the one next to his. I picked the lock of the door between the rooms and peeped in. Seeing no one, I went in. The place was empty. The bird had skipped." "Take the next train back to Philadelphia, and do the best you can to find out when Mitchel reaches there. He has gone back sure, and will be sick in bed in the morning, or my name is not Barnes. Bring me proof of his trip to and from New York, and I will give you fifty dollars. Skip." CHAPTER XI. MR. BARNES RECEIVES SEVERAL LETTERS.