Then, with a rush of displaced air that caused the balloon to sway violently, the aeroplane swept beneath it at the rate of an express train. Too late had the Huns spotted their quarry. To attempt to rise would result in collision with disastrous results to friend and foe. All the Huns could do was to depress the horizontal steering-rudders and dip sharply underneath the balloon before describing a curve and approaching it at an altitude that would enable them to use their weapons of offence. In this case the Germans hoped to recapture the two officers alive, and with that object in view they were endeavouring to perforate the envelope of the balloon sufficiently to send it with comparative slowness to the ground.
"Now!" exclaimed Fuller.
Both men hacked desperately with their knives they had found in the car. The basket dropped and was lost to sight in the darkness. Tressidar and his companion, clinging to the network, were almost unaware of any change of altitude, although there was a slight downdraught of air, until the balloon emerged from the bank of mist into the gathering darkness.
Tressidar gave a sigh of relief. There were no signs of the second German aeroplane. Evidently it was engaged, as was its consort, in hunting for the balloon in the fog, which was very much like looking for the proverbial needle in a bottle of hay—with the grave risk of an aerial collision thrown in.
By degrees the drone of the propellers died away and complete silence reigned. It was becoming bitterly cold. The two men, ill-clad for a night in the clouds, shivered violently. Their hands lost all sense of touch. Had it not been for the leather straps that encircled their bodies they would have been compelled to drop—to be dashed into unrecognisability upon the ground six thousand feet below.
Half an hour passed. Overhead the stars were shining brightly. Obliquely beneath them a dull blurr of light was visible. It was the searchlights of Sylt. Further away, and in the opposite direction, lights of varying intensity glimmered through the now dispersing fog.
"Hurrah!" exclaimed the flight sub. "The coastwise lights of Denmark. They can't be German, for the bounders are as cautious about showing as much as a candle-light as we are. That patch of luminosity must be the town of Esbjerg."
"We're getting nearer," declared Tressidar after another interval, during which the balloon had revolved half a dozen times on its own axis, for in the absence of the cable connecting it with the earth the supplementary gas-bag failed to serve its purpose of keeping the balloon steady.
"And falling," added Fuller. "We'll have to stand by for a jolly good old bump, I fancy."
They had now good reasons for supposing that they were over Danish territory, for beneath them numerous lights were twinkling. It was as yet only nine o'clock, and the villagers had not yet retired to rest. To the southward—for the aeronauts were now able to determine the cardinal points of the compass by means of the Pole Star—the lights ended abruptly, indicating the frontier line between a nation at peace and a nation at war.