The stairway ended in a circular well; silent--with no trace of exit! The rounded stones joined each other evenly--hermetically.

Carved on one of the slabs was one of the five flowered vines.

I pressed my fingers upon the calyxes, even as Larry had within the Moon Chamber.
A crack--horizontal, four feet wide--appeared on the wall; widened, and as the sinking slab that made it dropped to the level of our eyes, we looked through a hundred-feet-long rift in the living rock! The stone fell steadily--and we saw that it was a Cyclopean wedge set within the slit of the passageway.

It reached the level of our feet and stopped.

At the far end of this tunnel, whose floor was the polished rock that had, a moment before, fitted hermetically into its roof, was a low, narrow triangular opening through which light streamed.
"Nowhere to go but out!" grinned Larry.