The figure at the library desk started up as if electrified by the faint sound.
The circle of light from the flash lamp vanished in[Pg 9]stantly, leaving the room and hall in impenetrable gloom.
"He heard it," thought Nick, holding his breath. "He’s waiting and listening. He fears that some one is here, but he is not sure."
The waiting detective was right. He presently could hear the stealthy, catlike tread of the crook approaching the near door. It ceased after a moment, and Nick knew that the rascal then had reached the threshold and again was listening intently.
Nearly a minute passed, one minute of absolute silence and inky darkness.
Then a swift beam of light shot through the hall—but not under the stairs.
It was gone as quickly as it came, only to be repeated a moment later, leaping swiftly the entire length of the broad hall.
The crook saw no one, and he then stepped noiselessly toward the main stairway, where he paused once more to listen.
It was the move the detective had expected, and for which he was waiting. Rising noiselessly, Nick quickly glided nearer, then suddenly clasped the motionless black figure in his arms.
A thrill of amazement went through him from head to foot.