From away toward the street's eastern end had come a sudden, high-pitched cry, a thrilling scream which was repeated in the distance by a score of voices, and then succeeded by a dull roar. Rowan stepped out into the street, gazing down its length, lit by the suspended brilliance of the street-lights. A few of the groups on the sidewalks near by had stepped out beside him, and with these he stared down the long street's length toward the source of the shouting cries. He glimpsed, in a moment, a horde of figures running up the street toward him, a disorganized little mob which was giving utterance to a medley of hoarse shouts and screams. The mob parted, for a moment, and there roared through it a crowded automobile, racing up the street with immense speed, and past the wondering Rowan and those around him. And now he heard, simultaneously, a wild ringing of bells toward the south and a far-away crash which murmured faintly to his ears from the east. With every moment the clamor around him was increasing, the whole city awakening, and lights flashing out in windows on every side. By then the people around him had caught the contagion of panic and were hastening away toward the west also, but Rowan held his ground until the first running figures of the mob farther down the street were racing past him. Then he reached out and seized one of these, a shabby, middle-aged man whose face was contorted with panic. "What's the matter?" he cried, striving to make himself heard over the thunderous, increasing clamor about him. "What's happening?" The man he held bawled something indistinguishable in his ear, and at the same time wrenched frantically loose from his grasp, hurrying on. Some hundreds of feet down the street the main body of the mob was now racing toward Rowan, and then, beyond that mob, Rowan saw by the brilliant street-lamps the cause of their panic flight. Far down the street there was thundering toward him a gigantic creature which his eyes refused for the moment to credit, a titanic, dark thing whose tremendous, rumbling tread shook the very ground on which he himself stood. A hundred feet in length and a third of that in height it loomed, a colossal dark bulk upheld by four massive legs, tapering into a huge tail behind and carrying before it a long, sinuous neck which ended in a small, reptilian head. High up on the great thing's mighty, curving back clung some smaller creature which he could but vaguely glimpse, and down the street behind it were thundering a half-dozen more like itself, vast, incredible, charging down the street upon the madly screaming mob which fled before them. For one mad, whirling moment Rowan stared, and then he shouted aloud.