Close against the face of the outer wall something dangled.
A sudden eagerness seized him. He leaned far out of the window, doing so at no small risk, and reached along the wall toward the object. With the tip of his fingers he grasped it and drew it toward him.
It was a rope!
“The mystery is solved!” muttered Frank, with satisfaction. “This explains how the fellow entered my room.”
He shook the rope and looked upward. He could see that it ran over the sill of a window two stories above.
“Did he come down from there? Should have thought he would have selected a window directly over this. And did he climb back up this swaying, loosely dangling rope?”
Frank wondered not a little. And then, as he was leaning out of his window, the light of the street lamps showed him that a window beyond the dangling rope, on a level with his, was standing open.
The sight gave Merry a new idea.
“I believe I understand how the trick was worked,” he muttered.
“That must explain how the fellow was able to vanish so swiftly while my head was covered by the bedclothes. With the aid of this rope, he swung out from his window and into mine. He could do it easily and noiselessly. While my head was covered, he plunged out of the window, caught the rope, and swung back. That’s it!”