Another cloud of gas!--and a shattered ship!--and again the line emerged to correct its broken formation and drive once more toward the circling swarm. They came to meet them now, the clusters of red-striped fighting ships, and they tore in from all sides upon the American line, their hooked beaks gleaming in the sun. * * * * * And now, at an unseen signal, the formation broke. Each ship fought for its life, and the stabbing flashes of their guns made ceaseless jets of light against the smoke and gas clouds that were darkening the sky. "A dog-fight!" breathed Lieutenant McGuire; "and what a dog-fight!" His words were lost in the terrific thunder from above: the roar of the ships and the dull thuds of the guns engulfed them in a maelstrom of noise that battered like physical blows on the watchers below. He swore unconsciously and called down curses upon the enemy as he saw two fighters meet while the shining beak of a ship of the reds crashed through the body of an opposing craft. The red ship dipped at the bow; it backed off with terrific force; and from the curved beak a ship with the insignia of the red, white and blue slid downward in a swift fall to the death that waited. They had fought themselves clear, and the Americans, by what must have been arrangement or wireless order, went roaring to the heights. There were some who followed, but the guns of the speeding ships drove them off. Red-and-white shapes fell swiftly from the clouds where the fighting had been, and McGuire knew that his fellows had given an account of themselves in the fighting at close range. Again the thundering line was sharp and true, and another unswerving attack was launching itself from above. And again the deadly formation, with ever-increasing speed, drove into the enemy with flashing guns, then parted to close with the ones that drove crushingly upon them, while the sharper clatter of rapid-firing guns came to shatter the air. The fighting craft had been rising from their level field in a succession that seemed endless. They were all in the air now, and only the great transports remained on the paved field. * * * * * A red-striped fighter swept downward in retreat, and, from the smoke clouds, a silvery shape followed in pursuit. It reached the red and white one with its shells, and the great mass crashed with terrific impact on the field. Its pursuer must have seen the monsters still on the ground, and it swung to rake them with a shower of small-caliber shells. There were machine-guns rattling as it passed above the thronged reds--the troops who were huddled in terror in the open court. It tore on past them--past a figure in khaki who raced forward with the golden form of a girl within his arms, then released her to wave frantically as the silver ship shot by.