She paused significantly.

“Yes,” agreed Constance; “but Sleighbells is only a part of the system after all.  Who is the man at the top?”

Adele shrugged her shoulders and was silent.  Still, Constance did not fail to note a sudden look of suspicion which Adele shot at her.  Was Adele shielding some one?

Constance knew that some one must be getting rich from the traffic, probably selling hundreds of ounces a week and making thousands of dollars.  Somehow she felt a sort of indignation at the whole thing.  Who was it?  Who was the man higher up?

In the morning as she was working about her little kitchenette an idea came to her.  Why not hire the vacant apartment cross the hall from Adele?  An optician, who was a friend of hers, in the course of a recent conversation had mentioned an invention, a model of which he had made for the inventor.  She would try it.

Since, with Constance, the outlining of a plan was tantamount to the execution, it was not many hours later before she had both the apartment and the model of the invention.

Her wall separated her from the drug store and by careful calculation she determined about where came the little prescription department.  Carefully, so as to arouse no suspicion, she began to bore away at the wall with various tools, until finally she had a small, al-most imperceptible opening.  It was tedious work, and toward the end needed great care so as not to excite suspicion.  But finally she was rewarded.  Through it she could see just a trace of daylight, and by squinting could see a row of bottles on a shelf opposite.

Then, through the hole, she pushed a long, narrow tube, like a putty blower.  When at last she placed her eye at it, she gave a low exclamation of satisfaction.  She could now see the whole of the little room.

It was a detectascope, invented by Gaillard Smith, adapter of the detectaphone, an instrument built up on the principle of the cytoscope which physicians use to explore internally down the throat.  Only, in the end of the tube, instead of an ordinary lens, was placed what is known as a “fish-eye” lens, which had a range something like nature has given the eyes of fishes, hence the name.  Ordinarily cameras, because of the flatness of their lenses, have a range of only a few degrees, the greatest being scarcely more than ninety.  But this lens was globular, and, like a drop of water, refracted light from all directions.  When placed so that half of it caught the light it “saw” through an angle of 180 degrees, “saw” everything in the room instead of just that little row of bottles on the shelf opposite.

Constance set herself to watch, and it was not long before her suspicions were confirmed, and she was sure that this was nothing more than a “coke” joint.  Still she wondered whether Muller was the real source of the traffic of which Sleighbells was the messenger.  She was determined to find out.