"Urgent, sir! From the ZX-1!"

A moment later the captain of the ship, for the fleet's admiral was out in a launch inspecting what little of the fallen ZX-2 was still floating on the surface, was at the operator's side, listening amazedly.

The operator read off, word for word, what Chris Travers had sent. "... There was a contrivance planted aboard to blow up the ship and send it down in flames as the ZX-2 was. The thing that did it is—" he finished, and fell silent on that uncompleted sentence.

The captain's lined face expressed incredulity. "My God!" he burst out. "First the ZX-2, now— That all?"

"Yes, sir. I can't get any answer or connection."

They stared at each other. Finally the captain spluttered:

"Is some maniac loose in this fleet? Don't sit there like a fool, man! Get in touch with the Saratoga; tell 'em what you received; tell 'em to send some men up to that dirigible, wherever she is. We can't lose both of them!"

The operator's fingers skipped nimbly; even while he was speaking into the microphone, the red-faced captain had rushed back into the control bridge and was roaring:

"Signal the Admiral back here! Hurry!"