All at once, after an infinity of awesome, sightless, crawling up that concave and desperate precipice, I felt my head touch a solid thing, and I knew I must have gained the roof, or at least some kind of floor. In the darkness I raised my free hand and tested the barrier, finding it stone and immovable.

Then came a deadly circuit of the tower,

clinging to whatever holds the slimy wall could give;

till finally my testing hand found the barrier yielding,

and I turned upward again,

pushing the slab or door with my head as I used both hands in my fearful ascent. There was no light revealed above, and as my hands went higher I knew that my climb was for the nonce ended; since the slab was the trapdoor of an aperture leading to a level stone surface of greater circumference than the lower tower, no doubt the floor of some lofty and capacious observation chamber.

I crawled through carefully, and tried to prevent the heavy slab from falling back into place, but failed in the latter attempt. As I lay exhausted on the stone floor I heard the eerie echoes of its

fall,

hoped when necessary to pry it up again.