“Have you seen enough? because if so we’ll shut it up again.”
“One minute. How does it open and shut? Why, it isn’t a mere panel, it’s a solid block of stone.”
“Ah, that’s the secret of it. It is easily opened from within if you know how; but from without—well, it has never been discovered. The secret has been handed down among ourselves. It is always known to three persons, of which, needless to say, I am one.”
“How interesting! But if I were in there, and you and the other two were not get-at-able, what then?”
“You might as well be buried alive. Now, oblige me by looking out of that window once more.”
“If I mayn’t look, may I listen?”
“Certainly. Now you may turn again. Well, what did you hear?”
“Nothing.”
“Nothing? Well, see if you can tell which of the squares it was that opened.”
“This one. No; it doesn’t sound hollow. None of them do. I give it up.”