This they traversed for fully a mile, entering at length a large, square chamber where for a moment they paused. "I judge we are now at the base of the large pyramid," the professor voiced in an undertone. "It would naturally be the abode of the high priests." "But what do you suppose they want with us?" asked Diane. "That I am not disposed to conjecture," was her father's reply. But the note of anxiety in his voice was not lost on Diane, nor on Larry, who pressed her hand reassuringly. Now their captors led them from the room through a small door opening on another inclined gallery, whose turns they followed until all were out of breath from the climb. It ended abruptly on a short, level corridor with apertures to left and right. Into the latter they were led, finding themselves in a grotesquely furnished room, lit dimly by phosphorescent lamps. Swiftly the leader addressed Professor Stevens. Then all withdrew. The aperture was closed by a sliding block of stone. * * * * * For a moment they stood there silent, straining their eyes in the gloom to detect the details of their surroundings, which included several curious chairs and a number of mattings strewn on the tiled floor. "What did he say?" asked Diane at length, in a tremulous voice. "He said we will remain here for the night," her father replied, "and will be taken before the high priests at dawn." "At dawn!" exclaimed Larry. "How the deuce do they know when it is dawn, down here?" "By their calendars, which they have kept accurately," was the answer. "But there are many other questions you must both want to ask, so I shall anticipate them by telling you now what I have been able to learn. Suppose we first sit down, however. I for one am weary." Whereupon they drew up three of those curious chairs of some heavy wood carved with the hideous figures of this strange people's ancient gods, and Professor Stevens began. * * * * * Their sunken empire, as he had surmised, had indeed been the great island of Antillia and a colony of Atlantis. A series of earthquakes and tidal waves such as engulfed their homeland ages before had sent it down, and the estimated archaeological date of the final submergence--namely, 200 B. C.--was approximately correct. But long before this ultimate catastrophe, the bulk of the disheartened population had migrated to Central and South America, founding the Mayan and Incan dynasties. Many of the faithful had stayed on, however, among them most of the Cabiri or high priests, who either were loath to leave their temples or had been ordered by their gods to remain. At any rate, they had remained, and as the great island sank lower and lower, they had fortified themselves against the disaster in their pyramids, which by then alone remained above the surface.