In the side of the room formed by the wall of the tower, the mortar had fallen from between two stones, leaving one of them somewhat loose, but the castle wall at that point was fully sixteen feet thick, and it was impossible that the voice should have come through the layers of stone.
From my first acquaintance with Yolanda there had seemed to be a supernatural element in her nature, an elfin quality in her face and manner that could not be described.

Max had often told me that she impressed him in like manner.

The voice in our stone-girt chamber, coming as it did from nowhere, and resounding as it did everywhere, intensified that feeling till it was almost a conviction, though I am slow to accept supernatural explanations--a natural one usually exists.
Of course, there are rare instances of supernatural power vested in men and women, and Yolanda's great, burning eyes caused me at times, almost to believe that she was favored with it.
The voice that we had heard was unquestionably Yolanda's, but by what strange power it was enabled to penetrate our rock-ribbed prison and give tongues to the cold stones I could not guess, though I could not stop trying.

Here was another riddle set by this marvellous girl for my solving.

This riddle, however, helped to solve the first, and confirmed my belief that Yolanda was Mary of Burgundy.
After breakfast Max and I were taken to the great hall, where we found Castleman standing before the ducal throne, speaking to Charles.