Suddenly, as all three stood there debating that question, Professor Stevens uttered an exclamation and strode toward the pyramid. Following him with their eyes, they saw him pass through an aperture where a huge block of stone had been displaced—and disappear within.
The next moment they had joined him, to find themselves in a small flooded chamber at whose far end a narrow gallery sloped upward at a sharp angle.
The floor and walls were tiled, they noted, and showed none of the corrosion of the exterior surfaces. Indeed, so immaculate was the room that it might have been occupied but yesterday.
As they stood gazing around in wonder, scarcely daring to draw the natural inferences of this phenomena, there came a rasping sound, and, turning toward the entrance, they saw a massive section of masonry descend snugly into place.
They were trapped!
Standing there tense, speechless, they waited, wondering what would be the next move of this strange enemy who held them now so surely in his power.
Nor had they long to wait.
Almost immediately, there issued a gurgling sound from the inclined gallery, and turning their eyes in the direction of this new phenomena, they saw that the water level was receding, as though under pressure from above.
“Singular!” muttered Professor Stevens. “A sort of primitive lock. It seems incredible that human creatures could exist down here, but such appears to be the case.”