“Perhaps one of us brushed off the dust without realizing it. You tried to play a few notes on the organ, you know.”
“Yes, but I didn’t sit down on the bench, Rosanna.”
Losing interest in the organ, Penny began to search for the secret panel through which she was firmly convinced that the “ghost” had disappeared. As her eyes moved swiftly over the smooth wall, she suddenly uttered a low exclamation.
“See, Rosanna! The imprint of a man’s hand!”
The marking upon the wall was so faint that at first the other girl did not see it. But she too became excited as Penny pointed it out.
“How do you suppose it came to be there?” she asked in awe.
“I suspect our friend the organist was groping about in the dark searching for the secret panel. No doubt his hand was dusty and when he pressed it against the wall it left a faint imprint.”
“If you’re right, we have a valuable clue as to the location of the panel!”
Penny nodded eagerly. Already she was exploring the wall with her hand.
“It’s funny,” she murmured impatiently. “I’m as sure as anything that the panel is here——”