“A siren!” Hubert said to Ruth. The French women, too, had recognized the warning of a raid. A blast of a horn blew a loud staccato _alerte_; and the siren--it evidently was on some fast-driven car--diminished in the distance, wailing. Far off, but approaching closer, sounded deep, rolling reverberations; not like guns--Ruth knew guns now; nor yet like shells such as had burst on board the _Ribot_. They were aerial torpedoes, of tremendous violence, detonating in Paris buildings or upon the city streets. Guns were going now; and their shells were smashing high in the air. Ruth could see the flash of their break against the gleaming stars of the clear, cold sky; she could see rockets and glaring flares. The sound of the guns and the smash of the shells in the sky redoubled; a mighty flash lit the ground a half mile or more away across the railroad yards; it threw in brilliant silhouette for a second, roofs, trees, chimneys against a crimson inferno of flame. Hubert had the window open; and Ruth and the French women were kneeling side by side to look out and up. They could see little lights in the sky now; they could hear, between the smash of shells, the hum of airplane motors and the rattle of brief bursts of machine-gun fire. Airplanes of defense were up there fighting the Germans--French piloted those machines. But there might be Americans fighting there, too. Ruth had read that once or twice American pilots had been among those honored with the defense of Paris. She did not know whether it was true; she had meant to ask Gerry Hull. A few yards away in another compartment of another car--probably in the compartment where Lady Agnes sat--Ruth knew that he was kneeling before a window also gazing out; and she knew that the helpless impulse which stirred her with desire to be out there above to fly and fight was surging through him a thousand times intensified. She could feel even Hubert Lennon twist and sway at struggle with that impulse; how much more was Gerry Hull’s lithe, powerful body--that strong, rhythmically moving form which had carried her--straining now to join his comrades there above and to strike. A flare of flame, not sharp and jagged like the burst of shells, nor yet the streak of a rocket, nor like the glaring spot of a signal light, wavered across the stars. Something clouded it--smoke. It flung free from the smoke and dived, flaring bigger and brighter, trailing behind it a streamer of black which blanketed both rockets beyond and the stars; it dived on, burning. Ruth’s heart throbbed like a hammer in her throat. “_Chute d’un aéroplane!_” the French women cried. “Fall of an airplane!”