And yet it seemed to be drifting aimlessly back toward the fleet—erratically, as if not under complete control. And Dick could see the ships about a mile offshore, apparently drifting too. They were moving as no American squadron ever moved since the day the first hull was launched, for some of them, turned bow inward toward others, seemed upon the point of collision, while others were lagging on the edge of the formation, as if pointing for home.
Then suddenly the awful truth dawned upon Dick. The occupants of ships and dirigible alike had been overcome by the deadly gas.
ick banked, turned, leaned forward and shouted to Luke Evans, and, when the old man turned his head, indicated to him to sweep the tarmac with his ray.
The thread of black, broadening into a truncated cone, revealed nothing save the luminous outlines of the buildings. Apparently the tarmac was deserted. It was queer, too, that the silence of the night before was gone. Dick shouted again, to assure himself of what he knew already, and heard his own voice again.
Something had happened, something unexpected——or perhaps the crew of the Invisible Emperor, satisfied with the effects of the deadly gas, had not thought it necessary to go to any further trouble.
Suddenly Dick discovered that he was almost within the circle of the line of magnetic force. Hurriedly he threw over the stick and kicked rudder. It was not till he was again approaching the seashore that it occurred to him that the force, too, was not in operation.
He opened throttle wide and shot seaward. He must ascertain what had happened, and, if not too late, give warning without delay.
Then suddenly the vicious rattle of gunfire sounded in Dick's ears, and, materializing out of the sky, came Von Kettler's face. Startled for an instant, Dick quickly realized that it was Von Kettler in his plane, with his hood thrown back.