"There are other windows below," asserted Delmuth. "It would be possible — "
"Possible," agreed Benson. "Possible for a man to scale the wall, but highly improbable that he would risk it. Should we suspect The Shadow was outside our window, we could easily discover him."
"How?" Delmuth asked.
"I shall show you."
The old man went to a table and returned with a flashlight. He leaned deliberately from the window, and turned on the instrument. He focused its rays upon the wall below. When he again turned toward Delmuth, Benson wore a serious expression.
"Did you see anything?" questioned Delmuth.
"Yes and no," answered Benson softly. "I understand your qualms now, Delmuth."
"Why?"
"The entrance to the fire tower is twenty feet from this window." Benson's voice was little more than a whisper. "I observed a peculiar blackness there. It seemed to disappear as I turned the light directly toward it."
"That's the way it has been," said Delmuth hoarsely. "I have never seen a man — but I have observed signs of one. Always that way. What are we going to do about it, Benson?"