With this desperate yet praiseworthy resolution the flight-lieutenant swung his frail command about and began to climb steadily towards the mass of dark clouds. Ten minutes later the seaplane entered the lower edge of the nimbus. It was like tearing through a dense fog. All sense of direction was lost. Whether the machine was climbing, banking or descending was a matter of conjecture, since the darkness and the moisture made it impossible to consult the aeronautical instrument. Ahead was nothing but an opaque curtain of mist. On either side the tips of the planes merged into invisibility. Only astern were there any light-sparks from the hot exhaust throwing a faint, ruddy glare upon the wisps of trailing vapour that followed, circling and writhing, in the wake of the swiftly-moving machine. "If the Huns are anywhere in this stuff they'll get in a rare funk even if we don't run across them," thought Fuller, Unmindful of the danger of his own seeking he mentally pictured the panic-stricken condition of the raider, as hearing the roar of the seaplane's motors and unable to locate its position, they were in momentary peril of being rammed by an object tearing at ninety miles an hour through an optically impenetrable darkness. Kirkwood, too, realised the risk. With nerves a-tingle he awaited developments. Faith in Fuller's prowess gave him confidence. With one hand resting lightly on the lever operating the bomb-dropping gear he waited, ready at the first signal to release the missiles of annihilation. Suddenly the muffled roar of the exhaust gave place to a series of rapid explosions. Instinctively Kirkwood likened it to a boy rasping a stick along a row of iron palings. At the same time a succession of spurts of flame streaked overhead. The seaplane had only just scraped the underside of her antagonist. The upper planes had missed the Zeppelin's 'midship gondola by inches, and the flashes he had seen were from the airship's machine-gun as the Huns blazed furiously and erratically at their unseen but unpleasantly audible foe. Up spun 445B, until she seemed to stand almost on her tail. Then tilting until she was in imminent danger of side-slipping, she sought to make good her discovery. Vainly Fuller circled and circled, striving to pierce the vault of inky blackness. The Zeppelin was no longer there. Whether she had thrown out some more ballast or had trusted to her motors to bear her away from the unseen terror he knew not. He was not a man to admit defeat readily. "I'll make 'em have cold feet in any case," he decided, as he removed his mist-dimmed goggles and peered into the luminous compass bowl. "Due east till we get out of this cloud, and then I'll wait for the brute." Unfortunately, as far as he was concerned, Fuller's decision could not be carried out, for from no apparent cause the motors raced at unprecedented speed for a brief instant and then stopped.