The din was deafening, a confused uproar of rifles and machine-guns cracking and rattling out in front and banging noisily in their own trench, of bombs and grenades crashing sharply on the open or booming heavily in the trench bottom, of shells whooping and shrieking overhead or _crumping_ savagely on the ground, and, as a background of noise to all the other noises, the long rolling, unbroken thunder of the guns on both sides far up and down the lines. But above all the other din the lieutenant caught a new sound, a singing, whirring _boo-oo-oom_ that rose to a deep-throated roar with a sharp staccato _rap-tap-tap-tap_ running through it. He looked up towards the sound and saw, so close that he half ducked his head, a plunging shape, a flashing streak of silver light that swept over his head and dived straight at the ground beyond his trench, with stabbing jets of orange flame spitting out ahead of it. A bare fifty feet off the ground where the Germans crouched in their shell-holes "Silver Wings" swooped up sharply, curved over, dived again with the flashes of her gun flickering and streaming, and the bullets hailing down on the heads of the attackers. It was more than the Germans, lying open and exposed to the overhead attack, could bear. They scrambled from their holes, floundered and ran crouching back for the shelter of deeper trenches, while the lieutenant, seeing his chance, yelled and yelled again at his men to fire, and seized a rifle himself to help cut down the demoralised attack. He could see now how close a thing it had been for them, the weight of the attack that presently would have swarmed over them. The ground was alive with running, scrambling grey figures, until the bullets pelting amongst them cut them down or drove them headlong to cover again. Then his men stopped firing and watched with hoarse cheering and shouts the dives and upward leaps of the silvery shape, her skimmings along the ground, her upward wheeling climbs followed by the plunging dives with fire spitting and sparkling from her bows. The Germans were firing at her now with rifles and machine-guns until she turned on the spot where these last were nested, drove straight at them and poured long clattering bursts of fire upon them until they were silenced. Then she turned and flew over the broken British trenches so close that the men in them could see the leather-clad head and arm of the pilot leaning over the side, could see his wave to them, the flung packet that dropped with fluttering streamers down amongst them. The packet carried a note jerkingly scribbled in pencil: "Hang on. I'm taking word of where you are, so that they can send help to you. Good luck."