His sentence was never finished, for at that instant, from far behind, came a series of hideous yelps. Softened by distance though they were, the sounds were frightful enough to the ears of the fugitives. “They’ve struck our trail again,” remarked Seymour, stopping for a moment. Then a puzzled expression passed over his features, as a low, rumbling roar, not unlike far-away thunder, rolled up out of the distance, accompanied by a further series of wolfish cries. “I opine we’re going to strike trouble very shortly,” averred Silas, “though I allow I don’t hardly tumble to the meanin’ of this yer rumbling.” Quickly the rumbling grew into the pounding of giant hoofs, and the ground shook beneath the fugitives’ feet. “A stampede!” the baronet cried. “The devils have stampeded a herd of animals! Run for your lives!” But his friends needed no urging. They ran as men with the fear of death upon them, gazing eagerly to right and left in hope of finding some cave or cleft in the cliffs in which they might hide. But never a crack or a crevice appeared in the iron walls, and ever the pitiless thunder of the great hoofs drew nearer. It seemed as though nought could save the ill-fated trio from the vengeance which the devilish priest had designed for them. Then, almost at the last moment, an inspiration flashed into Haverly’s mind. He pulled up short, and, drawing his sheath-knife, sprang to where grew half a dozen or more huge puff-balls. Three of these he detached, handling them with great care. Carrying them out into the very centre of the gorge, he piled them in a heap. His friends had stopped their flight as they noted his strange actions, and now stood watching him, Seymour admiringly, Mervyn with blank astonishment depicted on every feature. “You’re a genius, Silas!” exclaimed the baronet, as, under the American’s orders, they placed a safe distance between themselves and the puff-balls. “I should never have thought of that.” “But surely,” Mervyn began, “you don’t mean to say that those things are explosive? Why----” “It was one of them same that bust the elk-hunters we told you about, anyway,” retorted the Yankee, his voice almost lost in the thunder of hoofs. The next instant a dozen huge forms loomed through the twilight, racing three abreast down the gorge. The foremost of them were almost upon the fungi pile, when Silas and the baronet fired, their shots crashing simultaneously into the puff-balls. A dazzling sheet of flame leapt high above the pile, illuminating for a moment the great shaggy bodies and huge curved tusks of the stampeding animals. “_Mammoths!”_ gasped the scientist. His exclamation was drowned in the shrill trumpeting of the terrified pachyderms, which was drowned in turn by the thunderous roar of the explosion as the puff-balls did their work.