The green cloud seemed to hesitate. Then the wind freshened a little, and it suddenly blew forward across No-Man’s Land, growing denser as it came. Before it, the sparrows fled suddenly, darting to the upper air with shrill chirpings of alarm. But one bird, taken unawares, beat his wings wildly for a moment, flying forward. Then he pitched downwards and the cloud rolled over him. “What is it?” uttered Wally. Before the parapet of the British trench ahead of them the cloud stood for a moment, and then toppled bodily into the trench. It fell as water falls like a heavy thing. From its green depths came hoarse shouts, and rifles suddenly went off in an irregular fusillade. Then the cloud rolled over, leaving the trench full of vapour, and stole towards the second British line. A great cry came ringing down the trench. “Gas! It’s their filthy gas!” It was a new thing, and no one was prepared for it. Across the Channel, England was shuddering over the first reports of the asphyxiating gas attacks, and the women of England were working night and day at the first half-million respirators to be sent out to the troops. But to the men in the trenches there had come only vague rumours of what the French and Canadians had suffered: and they had been slow to believe. It was not easy to realize, unseeing, the full horror of that most malignant device with which Science had blackened War. A few of the officers had respirators—dry, and comparatively useless. The men were utterly unprotected. Like sheep waiting for the slaughter they stood rigidly at attention, waiting for the evil green cloud that blew towards them, already poisoning the clean air with its noxious fumes. “Tie your handkerchiefs round your mouths and nostrils!” Jim Linton shouted. “Quick, Wally!” He caught at the younger boy’s handkerchief and knotted it swiftly. The corporal shook his head. “Most of ’em ain’t got no ’ankerchers, sir,” he said grimly. “They _will_ clean their rifles with ’em.” Then came another cry. “Look out—they’re coming!” Dimly, behind the cloud of gas, they could see shadowy forms clambering over the parapet of the enemy trench; German soldiers, unreal and horrible in their hideous respirators, with great goggle eyes of talc. Ahead, the quick spit of machine-guns broke out spitefully; and, as if in answer, Garrett’s Maxims opened fire. Then the gas was upon them: falling from above over the parapet, stealing like a live thing down the communication trench that led from the first line, where already the Germans were swarming. Men were choking, gasping, fighting for air; dropping their rifles as they tore at their collars, losing their heads altogether in the horror of the silent attack. A little way down the trench Anstruther was trying to rally them, his voice only audible for a few yards. Jim echoed him. “Come on, boys! it’s better in the open. Let’s get at them!”