Before he could complete the thought there came a sudden dull reverberation from the swamp to eastward, a quivering of the ground beneath him, a rumbling thunder rapidly nearing him. In sudden panic he shrank back into the forest at the broad path's edge, and the next moment their appeared in the east along that path a mighty shape, thundering down the path toward him and dimly visible in the starlight. It was a brontosaur, he saw, bearing one of the dark lizard-shapes which rode at the base of its great neck, thundering down the path toward the west in giant, earth-shaking strides. Another followed it, and another, until four had passed, and then the thunder of their great tread died away in the west, as they galloped on toward Brinton. Rowan stared after them and then, as a sudden thought flared in his brain, he crept again from the sheltering trees and moved steadily eastward into the swamp, following the great path by which the brontosaurs had come.
The path was beaten hard and flat, he found, and seemed to lead due eastward into the heart of the swamp. And as he followed it, as he crept onward, light came to his eyes from far ahead, a white brilliance which filtered faintly through the ranks of close-packed trees. Steadily Rowan crept on toward it, and then as its radiance began to strengthen he left the broad path and slipped again into the shelter of the forest, creeping forward ever more cautiously between the close-ranked trees and over the rotting, stagnant slime toward the source of the pallid light ahead.
A dull roar of sound came to his ears as he went on, a whistling, shrieking clamor as of some great wind which raged ceaselessly, louder and louder as he neared it. Through the trees ahead he glimpsed a broad open space lit by the white radiance, and dropped to his knees, crawling silently on. At last he had crept to the very edge of the open space and lay crouched in the slime behind a great tree, peering tensely forward.
Before him lay a great, flat mound of solid ground, elevated a few feet above the ooze of the swamp, roughly square in shape and fully one thousand feet across. It was quite bare and treeless, all vegetation upon it having apparently been sheared away, and was lit by a single globe of radiant white light suspended by a slender shaft of metal high above the great mound's surface. At the center of the broad, flat surface there yawned a tremendous pit which occupied half the mound's expanse, a vast circular shaft some hundreds of feet across whose smooth, perpendicular sides gleamed dully as though coated with metal. From where he crouched at the great mound's edge he could glimpse only the round mouth of the great shaft and a few feet of its downward-sinking sides, but he perceived that it was from this mighty pit that there roared upward the thunderous torrent of unceasing winds. Then his attention shifted from the great pit to the creatures grouped near its rim.
At the far edge of the great shaft there rose from the ground a strange, three-pillared structure of gleaming metal, bearing on an upheld plate a number of shining studs and a single large dial or wheel of metal. And beside this structure stood a knot of unearthly creatures, green-scaled, dark-eyed lizard-shapes like those he had glimpsed in the attack on Brinton. These were standing across the pit from him, at the very rim of the great shaft, and one or two of them were apparently staring down into the darkness of the shaft itself.
And now, over the raging shriek of winds from the pit, came another sound to the crouching Rowan's ears, a faint but deep bellowing which grew swiftly louder. He saw the lizard-men at the pit's edge stir, look downward, and then suddenly there rose up out of the great shaft's depths a great, round platform of metal, a mighty, disklike platform fully four hundred feet across which all but filled the mouth of the great pit as it rose, separated from that pit's edge by a tiny circular gap of a yard or less. Up from the dark depths of the shaft floated this great platform, slower and slower, and he saw that upon it were standing two of the gigantic, bellowing brontosaurs and some half-dozen more of the lizard-men. Smoothly the vast disk and its great burden drifted upward, until it hung level with the edges of the pit, its vast weight and the weight it bore suspended incredibly above the abyss. A moment it hung there, and in that moment the lizard-men on it stepped swiftly out onto the mound, prodding the two brontosaurs on before them. The empty platform hovered a moment longer at the pit's edge, and then began to sink slowly downward, gathering speed swiftly and dropping smoothly out of sight into the dark depths of the giant shaft.
Rowan gasped. That mighty platform, moving up the great shaft and down it, with upon it the great brontosaurs—from what unguessed depths below had it come? He saw that the lizard-men now were swinging up into curious, saddle-like seats affixed upon the backs of the giant beasts, and then heard them utter rasping cries, at which the two dinosaurs moved obediently forward, off the mound and onto the broad, beaten path which led from its edge westward through the swamp toward Brinton. In a moment the two great beasts and their riders had thundered down that path and disappeared, while on the mound were left only three of the lizard-creatures, who conversed in low, rasping tones.
Minutes passed while Rowan crouched there, watching them, and then one pointed downward into the shaft again, and in a moment there floated up once more the great disk-platform, but empty this time. It swept smoothly up once more to the edge of the shaft's mouth, hung motionless momentarily again at that edge, and then sank from sight once more. Rowan saw, then, that its motion was apparently automatic, and then before he could speculate further on it all his attention focused on the three lizard-men on the mound, who were walking together toward the great path which led west from that mound.
One seemed to point westward, where the red glare of light from burning Brinton still quivered in the sky, and then the three had disappeared down the path, evidently for a better view, since Rowan still could hear over the shriek of winds from the pit the rasping of their harsh, insectlike voices in the distance. Minutes he crouched, while the white-lit mound before him lay unoccupied, and then rose suddenly from his place of concealment and crept silently across the mound to the rim of the great pit. Tensely he craned forward, staring downward.