“Why, it looks as if it might have been changed!” Rosanna cried.

“And I think it has been. It’s my opinion that Max Laponi found your letter and the missing key. He’s a rank impostor.”

“Then you believe he is the one who has been frightening the household by playing on the pipe organ?”

“I haven’t made up my mind about that yet,” Penny returned thoughtfully. “But one thing I’m certain about. Laponi is a dangerous man.”

“Let’s get away from here right away.”

Penny laughed shortly. “I should say not! This mystery is growing more exciting every minute. I mean to discover Max Laponi’s little game!”

“But he may harm us,” Rosanna protested. “Especially if he suspects you’ve searched his room.”

“Laponi is armed,” Penny admitted with a frown. “But for that matter so are we.”

“You wouldn’t dare to carry that revolver!”

“I most certainly would. Not that I’d care to use it, but it might serve as protection.”