There was no mistaking the meaning of that whistling shriek. Whatever agency had held the Vandercook building aloft had now released its uncanny grip on the building, and thousands of tons of brick and mortar, of stone and steel, were plunging down in a mass from five thousand feet above the Hudson. The same force had also released the ill-fated men and women who had been carried aloft with the building. And there must have been hundreds of people inside side the building.

It fell as one piece, that great building. It didn't topple until it had almost reached the river and its shrieking plunge became meteor-like, the sound of its fall monstrous beyond imagining. The conference above the Hadley building fancied they could feel the outward rush of air displaced by the falling monster—and drew back in fear from the edge of the roof.

The Vandercook struck the surface of the Hudson and an uprush of geysering water for a few seconds blotted the great building from view. Then all Manhattan seemed to shudder. Most of it was perhaps fancy, but thousands of frightened Manhattanites saw that fall, heard the whistling, and felt the trembling of immovable Manhattan.

The great columns of water fell back into the turbulent Hudson which had received the plunging building. Not so much as a wooden desk showed above the surface as far as any one could see from shore. Not a soul had been saved. Shrieks of the doomed had never stopped from the moment the Vandercook building had started its mad journey aloft.

Jeter whirled on Hadley.

"Will you see that all my suggestions are carried out, Hadley?" he demanded.

Hadley, face gray as ashes, nodded.

From Manhattan rose the long abysmal wailing of a populace just finding its voice of fear after a stunning, numbing catastrophe.

"I'll do whatever you say, Jeter," said Hadley. "We all agreed before the arrival of Eyer and yourself that your advice would be followed if you chose to give any."

"Then listen," said Jeter, while Eyer stood quietly at his elbow, missing nothing. "Advise the people of New York to quit the city as quietly and in as orderly a manner as possible. Let the police commissioner look after that. Then get word to the leading aviation authorities, promoters, and fliers and have them get to our Mineola laboratory as fast as possible. We've kept much of the detail of construction of our space-ship secret, for obvious reasons. But the time has come to forget personal aggrandizement and the world must know all we have learned by our labor and research. Then see that every manufacturing agency, capable of even a little of what it will take for the program, is drafted to the work—by Federal statute if necessary—and turn out copies of our plane as quickly as God will let you."

Hadley's eyes were bulging. So were those of the others who had crowded close to listen. They seemed to think Jeter had taken leave of his senses, and yet—all had seen the Vandercook building perform the utterly impossible.

Hadley nodded.

"What do you want with the filers and others at your laboratory?"

"To listen to the details of construction of our space ship. Eyer will hold a couple of classes to explain everything. Then, when we've made things as clear as possible, Eyer and I will take off and get up to do our best to counteract the—whatever it is—that seems to be ruling the stratosphere. We'll do everything possible to hold the influences in check until you can send up other space ships to our assistance."

Hadley stared.

"You speak as though you expected to be up for a long time. Planes like yours aren't made overnight."

"Planes like ours must be made almost overnight—and have you forgotten that Kress was gone for three weeks, and yet had been dead but seventy-two hours when he landed on our roof? Incidentally, Hadley, that fall of his was guided by something or someone. He didn't fall on our roof by chance. He was dropped there, as a challenge to us!"

"That means?" said Hadley hoarsely.

"That everything we do is known to the intelligence of the stratosphere! That every move we make is watched!"

"God!" said Hadley.

Then Hadley straightened. His jaws became firm, his eyes lost their fear. He was like a good soldier receiving orders.

"All the power of the press will be massed to get the country to back your suggestions, Jeter. They seem good to me. Now get back to your ship and leave everything to me. Suppose you do encounter some intelligence in the stratosphere? How will you combat it, especially if it proves inimical—which to-night's horror would seem to prove?"

Jeter shrugged.

"We'll take such armament as we have. We have several drums of a deadly volatile gas. We have guns of great power, hurling projectiles of great velocity; but I feel all of that will be more or less useless. The intelligence up there—well, it knows everything we know and far more besides, for do any of us know how to strike at the earth from the stratosphere? Therefore our only weapons must be our own intelligence—at least that will be the program for Eyer and me. Later, when your planes which are yet to be built follow us up the sky, perhaps they will be better armed. I hope to be able to communicate information somehow, relative to whatever we find."

Hadley thrust out his hand.

"Good luck," he said simply.

Then he was gone and Jeter and Eyer were dropping swiftly down in the elevator to the street—to find that the streets of Manhattan had gone mad. The ban on electric lights had been lifted, and the faces of fear-ridden men and women were ghastly in the brilliance of thousands of lights. Traffic accidents were happening on every corner, at every intersection, and there were all too few police to manage traffic.

However, a motorcycle squad was ready to lead the way through the press for Eyer and Jeter—two grim-faced men now, who dared not look at each other, because each feared to show his abysmal fear to the other.

Automobiles raced past on either side of them driven by crazy men and hysterical women.

"Queensboro Bridge will be packed tight as a drum," said Eyer quietly.

Jeter didn't seem to hear. Eyer talked on softly, unbothered by Jeter's silence, knowing that Jeter wouldn't hear a word, that his partner had drawn into himself and was even now, perhaps, visualizing what they might encounter in the stratosphere. Eyer talked to give shape to his own thoughts.

A world gone mad, a world that fled from the menace which hung over Manhattan.... Jeter hoped that the calm brains of men like Hadley would at least be able to quiet the populace somewhat, else many of them would be self-destroyed, as men and women destroy one another in rushes for the exits during great theater fire alarms.

Fast as they traveled, some of the foremost airmen of the adjoining country had reached Mineola ahead of them. They understood that many of them had arrived by plane in obedience to word broadcast by Hadley. Hadley was doing his bit with a vengeance.

The partners reached their laboratory.

Their head servant met them at the door.

"A Mr. Hadley frantically telephoning, sir," he said to Jeter.

Jeter listened to Hadley's words—which were not so frantic now, as though Hadley had been numbed by the awful happenings.

"The new bridge between Manhattan and Jersey," said Hadley, "has just been lifted by whatever the unearthly force is. It was pulled up from its very foundations. It was crowded with cars as people fled from New York—and cars and people were lifted with the bridge. Awful irony was in the rest of the event. The great bridge was simply turned, along its entire length—which remained intact during the miracle—until it was parallel with the river and directly above midstream. Then it was dropped into the water."

"No telling how many lives were lost?" asked Jeter.

"No, and hundreds and thousands of lives are being lost every moment now. Frantic thousands are swamping boats of all sizes in their craze to get away. Dozens of overloaded vessels have capsized and the surface of the river is alive with doomed people, fighting the water and one another...."

Jeter clicked up the receiver on the horror, knowing there was nothing he could do. There would be no end to the loss of life until some measure of sanity had been argued into crazed humanity.

All the time he kept wondering.

What was doing all this awful business? He surmised that some anti-gravitational agency was responsible for the levitation of the Vandercook building, but what sort of intelligence was directing it? Was the intelligence human? Bestial? Maniacal? Or was it something from Outside? Jeter did not think the latter could be considered. He didn't believe that any planet, possibly inhabited, was close enough to make a visit possible. At any rate, he felt that there should be some sort of warning. He held to the belief that the whole thing was caused by human, and earthly, intelligence.

But why? The world was at peace. And yet....

Thousands of lives had been snuffed out, a twelve-story building had leaped five thousand feet into the air, and the world's biggest bridge had turned upstream as though turning its back against the mad traffic it had at last been called upon to bear.

Eyer was going over their plane with the visitors, men of intellect who were taking notes at top speed, men who knew planes and were quick to grasp new appliances.

"Have any of you got the whole story now?" Eyer asked.

A half dozen men nodded.

"Then pass your knowledge on to the others. Jeter and I must get ready to be off. Every minute we delay costs untold numbers of lives."

Willing hands rolled their ship out to their own private runway, while Jeter and Eyer made last minute preparations. There was the matter of food, of oxygen necessary so far above the Earth, of clothing. All had been provided for and their last duties were largely those of checking and rechecking, to make sure no fatal errors in judgment had been made.

Eyer was to fly the ship in the beginning.

A small crowd watched as the partners, white of face now in the last minutes of their stay on Earth—which they might never touch again in life—climbed into their cabin, which was capable of being sealed against the cold of the heights and the lack of breathable oxygen.

Nobody smiled at them, for the world had stopped smiling.

Nobody waved at them, for a wave would have been frivolous.

Nobody cheered or even shouted—but the two knew that the best wishes, the very hopes for life, of all the land, went with them into the ghastly unknown.