I started to obey, but turned to wait for Harry, who was gazing at Desiree.  His back was toward me and I could not see his face; his eyes must have held an appeal, for I saw Desiree’s lips part in a smile and heard her call: 

“You will see me!”

Then he joined me, and we began the descent together.

I found myself wondering how these half-civilized brutes had possibly managed to conceive the idea of the spiral stair.  It was known to neither the Aztecs nor the Incas, in America; nor to any of the primitive European or Asiatic civilizations.  But they had found a place where nothing else would do—­and they made it.  Another of the innumerable offspring of Mother Necessity.

I took time to note its construction.  It was rude enough, but a good job for all that.  It was not exactly circular; there were many angles, evidently following the softer strata in the rock; they had bowed to their material—­the way of the artist.

Even the height of the steps was irregular; some were scarcely more than three inches, while others were twelve or fourteen.  You may know we descended slowly and with care, especially when we had reached the point where no light came from above to aid us.  We found our guide waiting for us at the bottom, alone.

We followed him down the low and narrow passage through which we had previously come.  But when we reached the steps which led up to the passage above and to the cave where we had formerly been confined, he ignored them and turned to the right.  We hesitated.

“He’s alone,” said Harry.  “Shall we chuck the beggar?”

“We shall not, for that very reason,” I answered.  “It means that we are guests instead of captives, and far be it from us to outrage the laws of hospitality.  But seriously, the safest thing we can do is to follow him.”

The passage in which we now found ourselves was evidently no work of nature.  Even in the semidarkness the mark of man’s hand was apparent.  And the ceiling was low; another proof, for dwarfs do not build for the accommodation of giants.  But I had some faint idea of the pitiful inadequacy of their tools, and I found myself reflecting on the stupendous courage of the men who had undertaken such a task, even allowing for the fact that four hundred years had been allowed them for its completion.

Soon we reached a veritable maze of these passages.  We must have taken a dozen or more turns, first to the right, then to the left.  I had been marking our way on my memory as well as possible, but I soon gave up the attempt as hopeless.

Several times our guide turned so quickly that we could scarcely follow him.  When we signified by gestures our desire to go slower he seemed surprised; of course, he expected us to see in the dark as well as he.

Then a dim light appeared, growing brighter as we advanced.  Soon I saw that it came through an opening in the wall to our left, which we were approaching.  Before the opening the guide halted, motioning us to enter.