The mighty thousand-foot dirigible ZX-2, pride of the Navy and all America, had wobbled drunkenly in her path. She stuck her nose down, and then her whole vast frame shivered like a wind-whipped leaf as the dull roar of an explosion rolled over the sea. A huge sliver of hide was stripped from her as if by magic, revealing the skeleton of girders inside--revealing a tongue of crimson that licked out and welled into a hell of flame. Chris's blood froze. He watched the ZX-2 wallow in her death throes, writhe in the fiery doom that had struck her in seconds, that was devouring her with awful rapidity while thousands of men, blanched and trembling, gazed on helplessly. He saw her plunge, a blazing inferno, into the sea beneath.... There were old pals on her--buddies, gone in a flash of time! This wasn't a war game. This was tragedy, stark before his eyes. * * * * * The Black Fleet forgot its mimic battle. Radio telephone messages winged over the horizon to the approaching Blue Fleet. The Black dreadnoughts hove to; launches with ashen-faced men in white manning them dropped overboard; a dozen destroyers rolled in the swells around a crumbled, charred egg-shell that but minutes before had been an omnipotent giant of the sky. Chris Travers, aloft in sunlight suddenly bereft of its beauty, jammed the stick of the scout full over. He could do nothing, he knew. He could only return to the ZX-1 and tell the story of its sister as he had seen it. But why, he wondered as he flew almost blindly, had the ZX-2 so quickly flamed to oblivion? The helium of its inner bags had been uninflammable, as had the heavy oil of its fuel tanks; the ten engines were Diesels, and hence without the ordinary ignition system and gasoline. Safety devices by the score had been installed on board; nothing had been overlooked. And the weather, perfect. It was uncanny. It seemed totally unexplainable. Swarms of planes droned between sea and sky, all speeding in the one direction, west, to where the crumpled remnants of a dirigible were slipping quickly beneath the billows, beyond the sight of man. Planes of war game umpires, of officials, of newspaper correspondents and photographers. And soon a spectral, gleaming wisp of silver nosed out of the east, and the lone scout flying east dropped in altitude to meet its mother. Mechanically, his mind elsewhere, Chris shoved the button which reared the automatic clamp behind the cockpit in preparation for affixing the scout to the plane rack beneath the ZX-1. The dirigible, far in advance of the Blue Fleet, was roaring along at its full one hundred and fifty to hover over the grave of its sister. Chris eyed its course and changed his. To jockey into the rack, he had to pass the dirigible and come up underneath from its rear. * * * * * The air giant roared closer. As the distance between then loosened, Chris's brow wrinkled and he swore softly in puzzlement.