"Cliquot & Co., Diamonds, Second Floor Front."

A curious smile flitted over the young detective's face and he passed into the narrow hall and ascended the stairs muttering:

"I wonder if she's in there?"

In the upper hall he saw the name of the dealer in precious stones, painted on the ground-glass window.

Harry opened the door and strode in.

He found himself in a small office containing two huge Herring safes, guarded with burglar alarm cabinets. A long table covered with blue cloth served as a counter. Near the front windows was a bookkeeper working at his desk. At the rear a small compartment was partitioned off to serve as a private office.

A fat little Frenchman was behind the counter, but Harry did not see any signs of Clara La Croix.

A feeling of disappointment overcame him.

The salesman bowed, looked at him inquiringly, and asked politely:

"Well, sir, what can I do for you to-day?"