Down plunged the vanquished monoplane, spirally, erratically. The pilot was clinging desperately to the machine-gun. Even as the 'plane dashed through space the weapon, under the pressure of the Hun's hand, was aimlessly spitting out bullets. Again the wireless ticked off a message. It was from another seaplane that, although far away in the original cordon, had swung round and joined in the pursuit. Kirkwood's eyes twinkled as he deciphered the dots and dashes: "Congrats: your bird!" CHAPTER II A PRICE ON HIS HEAD FLIGHT SUB-LIEUTENANT BARCROFT scanned the expanse of water beneath him. The "Hippodrome" was now a mere speck far away to the west'ard. Four distinct trails of smoke betokened the fact that British destroyers were pelting to the scene of the seaplane's victory. On all other points of the compass the surface of the sea was deserted. "Wind up!" exclaimed Barcroft, using the speaking-tube for the first time since the opening of the duel. "I'm going to have a look at our bag." The A.P. began to reel in the trailing length of wireless aerial, while the pilot, shutting off the motor, began a spiral volplane towards the surface of the water. His "opposite number"--the seaplane that had tendered her congratulations--was also gliding down towards the spot where the Hun aeroplane had struck the surface. Barcroft recognised her pilot as Lieutenant John Fuller. The white patch of foam that had been created by the terrific impact of the wrecked machine had already vanished, but a series of everdiverging concentric circles of iridescent oil marked the spot. The monoplane had sunk like a stone. "No use going any lower," announced the Flight-sub, as he prepared to restart the engine. "Hold hard!" exclaimed the observer. "There's something floating. I believe, by smoke! it's the Boche pilot." "That alters the case, then," decided Barcroft. "We'll investigate still further." The Hun showed no signs of life. Kept up by his inflated jacket he floated on his back, his legs and arms trailing listlessly and his wide open eyes staring vacantly into the element through which a few minutes previously he had been flying for his life. The British seaplane alighted within a stone's throw of the corpse. Gravely both pilot and observer saluted the vanquished. Whether he deserved the honour or not the victors did not pause to consider. He might have been the cause of the deaths of a score or more inoffensive civilians--women and children perhaps; but death wipes out old scores. Barcroft and his companion merely recognised the dead airman as an opponent worthy of their steel, and as such he was entitled to the homage that one brave man pays to another. Of his past record they knew nothing. Their tribute was the spontaneous acknowledgment of a well-contested fight.