The next moment there came a hundred flashes of fire beneath them as the torpedoes and depth-charges struck, and then it seemed as though in a score of places beneath them the city was crumbling, disintegrating, beneath the force of the great explosions. The submarine was rocking and swaying perilously from the effect of those explosions, only the super-resistant hulls of the new-type craft enabling them to endure the shock, but even while Stevens heard the men near him shouting hoarsely he was aware that the massed boats were diving again, and again the thunderous detonations below came dully to their ears through the waters about them. But now he heard a sudden cry of alarm, taken up and repeated by all in the control room. From far away, all around the great city, there were hastening toward the attacking submarines scores of the giant striding-machines, their vast steps whirling them across the city with inconceivable swiftness, the great arm of each outstretched toward the submarines. An order was barked, and the craft's propellers spun swiftly as it headed upward to avoid those reaching, menacing arms, while the whole great fleet headed up also with the same purpose. The next moment, however, a spark of more brilliant white light broke into being in the city below them--a great, erect cylinder, they saw, that was suddenly shining with a dazzling radiance that darkened the white luminosity of the waters about it. And as it broke into being the submarine below seemed suddenly to waver, to halt, and then to be pulled slowly, steadily downward by great unseen hands, toward that shining cylinder. Stevens heard the motors throbbing in his own craft, its spinning propellers only serving to hold it in the same position, and heard a shout from Evans. "That cylinder!" he cried. "It's a great magnet of some kind--it's pulling our ships downward!" For now by dozens, by scores, by hundreds, the fleet's massed ships were being pulled downward, their screws thrashing the waters in vain, pulled down toward that mighty, dazzling beacon of light. The next moment the great striding-machines had reached them, were grasping them, crushing them, whirling them about like toys and hurling them far away to break and smash upon the globes below, spilling forth men and air-bubbles and great clouds of oil. Ever downward, downward, the mighty magnet of light pulled the helpless craft, while Stevens' own craft, highest of them all, could only resist that terrific pull by all the power of its humming motors. And among the helpless craft below he could see the great machines of the slug-people stalking about in terrific destruction, crushing and smashing the defenseless boats as they sought vainly to escape while Stevens' own craft sought frenziedly to win out of the remorseless grip that held it.