or a moment longer Von Kettler stood glaring; then, with a laugh of derision and a gesture of the hands he vanished from view. And, though they might have expected that denouement, the members of the Council leaped to their feet, staring incredulously at the place where he had been. Nothing of Von Kettler was visible, not even the eyes, and there sounded not the slightest footfall.
Dick sprang forward to the door, but his outstretched arms encountered only emptiness. In spite of the Secretary of State's instructions, he was almost minded to apprehend the man. If he could get him!
The corridor was empty. A guard of soldiers was at the entrance, but they did not block the entrance. Even now Von Kettler might be passing them! Why didn't his feet sound upon the floor? How could a bulky man glide so smoothly?
Perhaps because Dick was undecided what to do, Von Kettler escaped him. By the time he reached the guards he knew he had escaped. Suddenly there came an unexpected denouement. Somewhere on the White House lawn a guard challenged, fired. The snap of one of the silenced automatics answered him.
When Dick and the guards reached the spot, the man was lying in a crumpled heap.
"An airplane," he gasped. "Invisible airplane. I—bumped into it. Men—in it. The damned dogs!"
He died. Dick stared around him. There was no sign of any airplane on the lawn, nothing but the tents of the guards, white in the moonlight, and the grim array of anti-aircraft guns that Dick had placed there.
But behind the White House, in hastily constructed hangars, were a half-dozen of the latest pursuit airships—beautiful slim hulls, heavily armored, with armored turrets containing each a quick-firer with the new armor-piercing bullets. One of these ships, Dick's own, was kept perpetually warmed and ready to take the air.