had failed to detect, through the superimposed gauze, the slightest irregularity there. But, the trap opened, a perfectly clear view of the room could be obtained through the gauze, which, by reason of its texture, also admitted a current of air.
This matter settled, M. Max proceeded carefully to examine the entire room foot by foot. Opening the door in one corner, he entered the bathroom, in which, as in the outer apartment, an electric light was burning. No window was discoverable, and not even an opening for ventilation purposes. The latter fact he might have deduced from the stagnation of the atmosphere.
Half an hour or more he spent in this fashion, without having discovered anything beyond the secret of the observation trap. Again he took out his pocket-knife, which was a large one with a handsome mother-o’-pearl handle. Although Mr. Ho-Pin had examined this carefully, he had solved only half of its secrets. M. Max extracted a little pair of tweezers from the slot in which they were lodged—as Ho-Pin had not neglected to do; but Ho-Pin, having looked at the tweezers, had returned them to their place: M. Max did not do so. He opened the entire knife as though it had been a box, and revealed within it a tiny set of appliances designed principally for the desecration of locks!
Selecting one of these, he took up his watch from the table upon which it lay, and approached the door. It possessed a lever handle of the Conti-
