Small wonder that Mervyn was half mad with terror, as, clutching desperately at the monster’s bony necklet, he strove to prevent the brute unseating him, and pounding him to a jelly beneath its terrible hoofs, which, even now, were trampling the floor of the glade in a paroxysm of fury. At length, finding himself utterly unable to get rid of the encumbrance, the monster broke out of the glade at a lumbering trot, and thundered across the plain which lay beyond. As for Garth and Seymour, they stood for a few seconds as though stunned. The thing had happened so suddenly that it had paralysed their powers of action, dried up the fountain of their energies. When at last they recovered their scattered wits, the two scrambled recklessly down the side of the ridge and hurried out on to the plain. But the thunderous tread of the Triceratops had already died away, and there was no sign of their friend. “We must follow the trail,” Seymour muttered, pointing to the broadly-defined track made by the monster’s hoofs, which stretched away into the darkness. “Yes,” Garth assented, with a quiver in his voice, “and may Heaven grant we find him safe!” The plain looked particularly gloomy and uninviting, owing to the almost total absence of fungi, save for a few isolated clumps, whose presence but made the twilight more gloomy by contrast. Yet over it the twain must go if they would find their friend, daring its hidden dangers, and braving all the terrors of this unknown land. So, looking well to their weapons, the two comrades stepped out. Hardly had they taken half a dozen paces when once more that thrilling, wolfish cry arose, but this time it came from somewhere close at hand. Seymour pulled up sharply, listening intently. “By Jove! they’ve scented us!” he cried as the howl was repeated. “Back into the valley; we shall stand a better chance there.” Quick as a flash he turned, and leapt for the glade they had left. Garth, following, tripped over a trailing fungus, and, losing his footing, pitched heavily to earth. Ere he could rise a bony hand gripped his neck; he received a sharp blow on the head, and then consciousness left him. “Where are you, Garth?” Seymour called; “this is the way.” Alarmed at receiving no answer, the baronet retraced his steps. “Garth!” he cried. “Hilton! Where are you, old chap?” But there was no answer, save the echoes which seemed to mock; even the wolf-like howls had ceased, and Seymour appeared to be the only living thing in the whole ghostly underworld. Anxiously he searched the ground around, but not a trace could he find of his comrade. For over an hour he sought diligently, eagerly, yet all his efforts were vain. It seemed as though the earth had opened and swallowed the unfortunate inventor. Mervyn’s accident had seemed terrible enough, but Garth’s disappearance eclipsed even that. It was so appallingly mysterious!