Then: "Dodge that vapor," ordered General Lozier. The plane wavered in signal to the others and swung sharply to the left. Each man knew the flaming death that was theirs if the fire of their exhaust touched that explosive mixture of hydrogen and air. The great bubble turned with them and paralleled their course. "He's watching us," said Riley, "giving us the once over, the slimy devil. Ain't there a gun on this ship?" The General addressed his superior. Even above the roar of the motors his voice seemed quiet, assured. "We must not land now," he said. "We can't land at North Island. It would focus their attention upon our defenses. That thing--whatever it is--is looking for a vulnerable spot. We must.... Hold on--there he goes!" The big bulb shot upward. It slanted above them, and hovered there. "I think he is about to attack," said the General quietly. And, to the commander of their squadron: "It's in your hands now, Captain. It's your fight." The Captain nodded and squinted above. "He's got to throw heavier stuff than that," he remarked. A small object was falling from the cloud. It passed close to their ship. "Half-pint size," said Cyrus Thurston, and laughed in derision. There was something ludicrous in the futility of the attack. He stuck his head from a window into the gale they created. He sheltered his eyes to try to follow the missile in its fall. * * * * * They were over the city. The criss-cross of streets made a grill-work of lines; tall buildings were dwarfed from this three thousand foot altitude. The sun slanted across a projecting promontory to make golden ripples on a blue sea and the city sparkled back in the clear air. Tiny white faces were massed in the streets, huddled in clusters where the futile black missile had vanished. And then--then the city was gone.... A white cloud-bank billowed and mushroomed. Slowly, it seemed to the watcher--so slowly. It was done in the fraction of a second. Yet in that brief time his eyes registered the chaotic sweep in advance of the cloud. There came a crashing of buildings in some monster whirlwind, a white cloud engulfing it all.... It was rising--was on them. "God," thought Thurston, "why can't I move!" The plane lifted and lurched. A thunder of sound crashed against them, an intolerable force. They were crushed to the floor as the plane was hurled over and upward. Out of the mad whirling tangle of flying bodies, Thurston glimpsed one clear picture. The face of the pilot hung battered and blood-covered before him, and over the limp body the hand of Slim Riley clutched at the switch. "Bully boy," he said dazedly, "he's cutting the motors...." The thought ended in blackness. There was no sound of engines or beating propellers when he came to his senses. Something lay heavy upon him. He pushed it to one side. It was the body of General Lozier. * * * * *