It irritated Mr. Barnes, the way in which Mr. Mitchel always seemed to belittle his skill. He was a trifle angry, therefore, as he made his next bold stroke.

"I will tell you, ladies and gentlemen, where the thief might have hidden the jewels, on the train—a place which no one thought of searching, not even myself."

"Oh! tell us!" exclaimed Dora. The two men looked interested, nothing more. Emily had come behind Mr. Mitchel, and slyly slipped her hand within his.

"The woman carried the jewels in a satchel. Suppose the thief had stolen the satchel and thrown it from the window. Missing that, the woman would have naturally concluded that the jewels were gone, would she not? Very well. The thief might have hidden the jewels in her own pocket whilst she slept." Mr. Barnes had hoped much from this proposition, but it was a distinct failure. Either that was not the thief's method, or else Mr. Mitchel and Mr. Thauret were both innocent. Both smiled incredulously. The former spoke:

"That is too far-fetched, Mr. Barnes. How do you suppose that he would regain possession of the gems?"

"By murdering the woman," answered the detective. Again he failed, for neither of the men winced. Mr. Barnes was foiled for the moment, but not entirely discouraged. The start which both men had made, when he suggested that the stolen property had been hidden off the train, still remained to be explained.

"Come! Come! Mr. Barnes," said Mr. Mitchel patting his shoulder familiarly, "don't let this case upset you so. When you go so far for a theory, you do not show the skill which you displayed in tracking Pettingill. Why even I can get you a better one than that."

"You must not think me quite a fool, Mr. Mitchel. If my theory seems preposterous, it does not follow that it is the only one at my command. We detectives must look at these cases from all lights. I will wager that I can tell you what your theory is?"

"Good! I am glad New York has such a clever man to defend her. I accept your wager. Here, I will write my idea on a bit of paper. If you guess it I owe you an invitation to a good dinner." Mr. Mitchel wrote a few lines on the back of an envelope and handed it to Dora.