But on this great elongated gas bag, there was nothing to reef. She could only turn tail and race the wind for her life. Telegraph orders, rushed from control-room to engine quarters, brought the huge dirigible up short, rearing and plunging like a frightened steed. At touch of the engineers, the marvelous mechanism of drive-shaft and bevel gear tilted each propeller on its axis to throw the ship into reverse and back it around. For so huge a bulk, she wheeled in her tracks with amazing speed. There was need of speed! Even in that short time while receiving the wirelessed warning out of the air and plunging into retreat, great banks of cloud had reared themselves on the horizon, looming black and sinister. With every passing moment they rolled up, darker, heavier. With awful menace, a great droning roar filled the air. The Nardak was turning back on the very fringes of an onrushing storm that seemed to leap out of the nowhere. With a rumble the wind-clouds loosed their first furious gusts in a rage that tore the clouds themselves into a jagged pattern. Ragged openings gave vistas into the still more fearful storm that they had masked! Through the barrage of thunderheads burst a three-headed tornado, three huge twisting wind-spouts that seemed to reach from earth to sky. Writhing, speeding, twisting across the sky, they pursued the Nardak like great devouring serpents. Devourers they were! Terrific wind velocity within those whirling storms could pluck the hair from the human head, could tear a man limb from limb, could wrench a great airship into shreds and splinters.