"Our guest!" amended Marjorie, with a warm smile.

Next morning Blake motored Kendrick out to the Brooklyn Laboratory of the Consolidated Electric Utilities Corporation and installed him there.

Then he left--to return at noon with the promised delegation of generals, admirals, statesmen and financiers.

They were all frankly sceptical, though realizing that Henderson Blake was not a man given to exaggeration. Nor did their scepticism altogether vanish when Kendrick had ended his bizarre story with a demonstration of the invisibility device.

Murmurs of amazement ran around the laboratory, it is true, but the more hard-headed of his spectators charged him with having invented the apparatus himself. Though they didn't come right out and say so, they seemed to imply that he was seeking publicity.

Annoyedly, Kendrick tried to refute their charges. But even as he was summoning words, refutation utter and complete came from the air.

A low, humming vibration sounded, grew in volume till it filled the room--and as suddenly ceased: The light of midday faded to twilight.

"_The disc!_" gasped Kendrick, rushing to the west windows.

They followed, tense with awe. And there, between earth and sun, its myriad towers and spires refracting a weird radiance, hovered that vast flying city.

"My G.o.d!" muttered a famous general, staring as though he had seen a ghost.

A great statesman opened his lips, but no words came.

"Appalling! Incredible!" burst from others of that stunned a.s.semblage.

Their comments were cut short by a broadcast voice, thin and clear, tremendously amplified, a voice Kendrick recognized at once as that of Cor.

"People of America!" it said. "We of the planet Vada have come to conquer your country. You will be given forty-eight hours to lay down your arms. If complete surrender has not been made by high noon, two days from now, New York will be destroyed."

The voice ceased. The humming recommenced--waned in volume till it died away. Twilight turned once more to midday.

Peering fixedly through the west windows of the laboratory, the little a.s.semblage saw the disc swallowed up in the clear blue sky.

Then they turned, faced one another gravely.

Outside, on the streets, confusion reigned. In newspaper plants, presses were whirling. In telegraph and cable offices, keys were ticking. From radio towers, waves were speeding.

Within an hour, the nation and the world knew of this planetary invader and its staggering ultimatum.

Naturally, the government at Washington refused to meet these shameful terms. Military and naval forces were rushed to the threatened metropolis. The Atlantic Fleet steamed up from Hampton Roads under forced draught and a.s.sembled in the outer harbor. Thousands of planes gathered at Mitch.e.l.l Field and other nearby aerodromes.

But where was the enemy? He must be miles up in s.p.a.ce, Kendrick knew, as he toiled feverishly in the laboratory over his experiment after a sleepless night. For had that flying city been nearer earth, it could not have maintained invisibility without that peculiar humming vibration.

Scout planes urged on by impatient squadron commanders, climbed till they reached their ceilings, searching in vain. They could encounter nothing, see nothing of the invader.

Thus pa.s.sed a morning of growing tension.

But by noon of that day, with a bare twenty-four hours left before the expiration of the ultimatum, the disc came down, showed itself boldly.

There followed stunning disasters.

One salvo, and the ray shot down--the Atlantic Fleet, the pride of America, burst and melted in flaming h.e.l.l. Squadrons of planes, carrying tons of bombs, frizzled like moths in the air. Mighty projectiles hurled by land batteries were deflected off on wild trajectories.

Appalled, the nation and the world followed in lurid extras these crushing defeats.

By nightfall of that day, all seemed lost. All opposition had been obliterated. America must capitulate or perish. It had until the next noon to decide which.

Meanwhile, in that great Brooklyn laboratory, Kendrick was working against time, besieged by frantic delegations of the nation's leaders.

They knew now that their one hope lay in him. Was he succeeding? Was there even any hope?

Face haggard, eyes bloodshot from lack of sleep, he waved them away, went on with his work.

"I will tell you--as soon as I know."

That was all he would say.

Followed a night that was the blackest in all history, though the myriad stars of heaven shone tauntingly brilliant in the summer sky.

At length, as dawn was breaking. Kendrick paused in his labors.

"There!" he said, grimly, surveying an apparatus that seemed to involve the entire facilities of the laboratory. "It is done! Now then--will it work?"

The delegation were called to witness the test.

Henderson Blake was among them, as was Marjorie. She stepped forward, as he prepared to make the demonstration.

"I _know_, somehow, you're going to be successful!" she murmured, pressing his hand, meeting his eyes with a smile of confidence.

"I hope you're right--Marjorie!" he replied, letting slip the last word almost unconsciously.

Her face colored warmly as the stepped back and rejoined her father.

Kendrick's heart was beating fast as he turned to his instruments. How could he fail, with faith like that behind him?--love, even, perhaps!

He mustn't fail--nor would he, if his theories were sound.

Addressing the a.s.semblage, he explained briefly the complicated apparatus.

"These towers," he said, pointing to four steel structures about ten feet high, arranged at the corners of a square roughly twenty feet across, "are miniature radio masts. The area enclosed by them, we will a.s.sume, is the city of New York. That metal disc suspended above the area represents the invader. It contains a miniature heat-generator such as I was experimenting with recently in the Arizona desert."

He paused, threw a switch. Somewhere in the laboratory a dynamo began to whir.