He smoked in silence for an hour, with the key of Mrs. van Dietrich’s bedroom and the half-burned wax match in his fingers. He examined them alternately through the magnifying glass and tried to build a hypothesis on either one or the other, or both.

Suddenly there was a sharp rap at his door. As he opened it, James Mallory stepped inside and stared at him with blinking eyes, while his heavy cheeks, usually beet red, were a yellowish white.

“What’s the matter?� demanded Nick Carter sharply.

“More trouble!� blurted out Mallory. “It seems as if the foul fiend himself is taking a hand in running this hotel.�

“Never mind about that!� interrupted the detective impatiently. “What is the specific trouble now?�

“Another of our guests has mysteriously disappeared,� wailed Mallory. “Mr. Harvey L. Drago, the big Wall Street banker.�

“Disappeared?� cried Nick Carter. “How? From his bedroom?�

“No. From the golf links!�

“That so? This is getting interesting,� observed Nick. “Sit down and tell me all about it, Mr. Mallory.�

CHAPTER III.
LONG-DISTANCE OBSERVATIONS.