She threw out her hands in a wildly appealing gesture.

“And if Lynn finds that the necklace in our wall safe is of paste--as he will find, for he is an expert in diamonds—­oh—­what shall I do?  Can’t you—­can’t you find my necklace?”

Kennedy was following her now eagerly.  “You were blackmailed out of the money?” he queried casually, masking his question.

There was a sudden, impulsive drooping of her mouth, an evasion and keen wariness in her eyes.  “I can’t see that that has anything to do with the robbery,” she answered in a low voice.

“I beg your pardon,” corrected Kennedy quickly.  “Perhaps not.  I’m sorry.  Force of habit, I suppose.  You don’t know anything more about the robbery?”

“N—­no, only that it seems impossible that it could have happened in a place that has the wonderful burglar alarm protection that Mr. Schloss described to me.”

“You know him pretty well?”

“Only through this transaction,” she replied hastily.  “I wish to heaven I had never heard of him.”

The telephone rang insistently.

“Mrs. Moulton,” said Kennedy, as he returned the receiver to the hook, “it may interest you to know that the burglar alarm company has just called me up about the same case.  If I had need of an added incentive, which I hope you will believe I have not, that might furnish it.  I will do my best,” he repeated.

“Thank you—­a thousand times,” she cried fervently, and, had I been Craig, I think I should have needed no more thanks than the look she gave him as he accompanied her to the door of our apartment.

It was still early and the eager crowds were pushing their way to business through the narrow network of downtown streets as Kennedy and I entered a large office on lower Broadway in the heart of the jewelry trade and financial district.

“One of the most amazing robberies that has ever been attempted has been reported to us this morning,” announced James McLear, manager of the Hale Electric Protection, adding with a look half of anxiety, half of skepticism, “that is, if it is true.”

McLear was a stocky man, of powerful build and voice and a general appearance of having been once well connected with the city detective force before an attractive offer had taken him into this position of great responsibility.

“Herman Schloss, one of the best known of Maiden Lane jewelers,” he continued, “has been robbed of goods worth two or three hundred thousand dollars—­and in spite of every modern protection.  So that you will get it clearly, let me show you what we do here.”

He ushered us into a large room, on the walls of which were hundreds of little indicators.  From the front they looked like rows of little square compartments, tier on tier, about the size of ordinary post office boxes.  Closer examination showed that each was equipped with a delicate needle arranged to oscillate backward and forward upon the very minutest interference with the electric current.  Under the boxes, each of which bore a number, was a series of drops and buzzers numbered to correspond with the boxes.