“Oh, come now,” said Zizi, “Mr. Wise does know. He is not at all vain glorious, or he would tell you himself. But he prefers to let Mr. Stebbins tell.”

“Is that so, Mr. Wise?” asked Professor Hardwick, eagerly. “If you have discovered the secret entrance, I wish you would say so. I feel chagrined that my own reasoning powers have given me no hint.”

“I have satisfied myself of the means and the location of the entrance,” Wise returned, “but I have not examined the place definitely enough to find the hidden spring that must be there.”

“You know that much!” cried Stebbins, in amazement.

“Yes, largely by elimination. There are no hollow walls, no false locks, no sliding panels,—it seems to me there is no logical hidden entrance, but through one of those columns,” and he pointed to the great bronze columns that flanked the doorway.

“By golly!” and Stebbins stared at the speaker. “You’ve hit it, sir!”

“I could, of course, find the secret spring, which must be concealed in the ornamentation,” Wise went on, “but I’ve hesitated to draw attention to the columns by working at them. Suppose we let Mr. Stebbins tell us, and not try to find what we know must be cleverly concealed.”

“But wait a minute,” pleaded Hardwick. “I’m terribly interested in this proof of Mr. Wise’s perspicacity. You needn’t touch the column, but tell us your theory of its use. Is there a sliding opening in the solid bronze?”

“I think not,” and Wise smiled. “I may be all wrong, I really haven’t looked closely, but my belief is that one or both of those great columns, which, as you see, are half in and half out of the hall, must swing round, revolve, you know,—and so open a way out.”

“Exactly right!” and Stebbins sprang toward the column that was on the side of the hall toward the Room with the Tassels. “That’s the secret. Nobody ever so much as dreamed of it before! See, you merely press this acorn in this bronze oak wreath, half-way up, press it pretty hard, and the column swings round.”