Far back there something dark fluttered in the night air. It was seized and passed from hand to hand. It reached the circle of light and waved high above the center of the crowd, a banner of crimson, tossing like a beacon over the swarm of black heads, defiant, audacious: the Red Flag. And then came a new sound. It began in the heart of the mob and spread outwards like circles in water broken by a dropped stone. It did not stop the other noises; it assimilated them. It was low, but strong; it seemed to contain all the history of past wrongs, all the arsenal of present determination; but it was touched with far hopes and freighted with tremendous dreams. It was a chant, a song, a hymn, and all the crowd was singing it with the strength of a thousand pair of lungs. "What’s that?" asked Luke, although he expected no answer. But the girl gave him one. "It’s a thing called ’The International,’" she said, her voice trembling. "I heard it once in Paris. It’s a terrible song." Luke’s eyes were caught by a movement at the window of one of the tumbledown dwellings across the street. He saw the window open and a frowsy woman lean out. She held something white in her hands. She raised it, then dashed its contents toward the nearest soldier. The shot fell short, and two men in the crowd were drenched. The hymn ended in a shriek. The mob believed that the insult had come from the factory and instantly resolved itself into a fuming whirlpool. Luke saw tossed aside people who were evidently strike-leaders frantically trying to quiet their one-time followers, but he did not guess the purport of the new commotion in the seething mass. Then he saw something that made him jerk Betty away from the window and fling her against the wall at its side. There was a crash—a pause—a tinkling. A gust of air, fresh and cool, invaded the room. A missile had broken the window. A whole volley followed, smashing more glass and battering at the factory walls. The mob was using the coals from the dismantled wagon that Luke had noticed in the street hours ago. [Illustration: THE MOB WAS USING THE COAL FROM THE DISMANTLED WAGON] Somebody had been pounding unheard at the office-door. Luke saw the door bend and ran to it. He flung it wide. Breil stood there, his revolver in his hand. "I’ve got to disturb you——" he began, and, though he shouted, his voice did not reach to where Betty stood against the wall. "That’s all right," called Luke. "I’ve been a fool and a coward to stay here. Give me that gun." He wrenched the weapon from Breil’s resisting hand. He leaped to Betty and slipped the revolver to her. "Got to go downstairs," he cried to her, for the broken window let in a roar that made ordinary speaking tones futile. "Bolt the door after us! You’ll be safe! We’ll fall back to the stairs, if we have to fall back. Good-bye!"