It was at this juncture that Derek Daventry, one of the host of aerial fighters, found himself flying at a few hundred feet above the Boche lines. In the reflected glare of the rifle- and machine-gun fire he could discern the array of tanks advancing. The slow-moving tanks were in the van, their _raison d'être_ to flatten down the hostile wire and pave a way for the whippets and "twenty-milers" of the land-fleet. Machine-gun bullets were rattling against their armoured snouts, while here and there bursts of vivid-red flame gave token that the anti-tank bullets--steel-cored and copper-encased missiles--had put more than one tank out of action. All this Derek took in as the result of a few seconds' flight. Then, over the hostile front, his work began. In darkness, save for the intermittent flashes of the guns, the British 'planes sped to and fro. Unavoidable collisions brought friends crashing to earth; oft-times the machines were flying blindly through clouds of black, nauseating smoke. Rocking, side-slipping, bumping, and banking, the aerial-fleet continued its work in hammering with the land-armada of tanks. Machine-gunning, bombing, and dropping poison-gas cylinders, the airmen hovered remorselessly over the now-demoralized Boches, while the tanks, surging onwards, beat down acres of barbed-wire and flattened out whole sectors of trenches. Derek had just fired his ninth tray of ammunition when he felt the joy-stick give. A fragment of shell had severed the "nerve-centre" of the biplane, and the 'bus was now practically out of control. A touch upon the rudder-bar turned EG 19 in the direction of "home", but almost immediately the engine "konked". In the darkness it was impossible to see what had happened, but another fragment of shell had lodged fairly in the magneto. EG 19 had to come down. How she came down depended upon sheer luck, since the skill and nerve of the pilot were useless to avoid the threatened calamity. Derek steeled himself to meet the tremendous crash, but the shock never came. By one of those eccentricities of movement that aerial-craft occasionally perform, the biplane flattened out within twenty feet of the ground, dipped her nose, and then pancaked upon the shelving side of a large shell-crater. Without a scratch the pilot scrambled out of the fuselage and gained the ground. He promptly threw himself at full length in the stiff mud that lay in the bottom of the crater, and listened to the appalling racket overhead. Shells of light calibre were screeching and bursting all around, their uproar punctuated by the heavier concussion of aerial-bombs. A crescendo of machine-gun fire added to the deafening roar, while the hail of bullets directed upon the imperturbable tanks sounded like a continuous tattoo.