t his findings.

All stuffed their ears with cotton wool, and crowded against one end
of the chamber. Anthony had the end of a long double wire in his hand,
and it curled across the floor to the farther wall. He pressed the
button of a pear-switch--and there was a concussion that hurled the
watchers against the wall behind them. A great gap appeared in the
farther wall, beyond it a black chasm, and a helicopter that was dimly
illumined by the light from within the room. A quick inspection of
the flier revealed that its alumino-steeloid had been unaffected by
the passage of time, and Allan climbed into it. A wave of his hand
simulated an insouciance he did not feel. Then he was rising through
darkness. The sun's light struck down and enveloped him, and he was in
the open air. He rose above the trees.

Desolation spread out beneath him. In all the vastness that unfolded
as the lone 'copter climbed into a clear sky, nothing moved. The air,
that from babyhood Allan had seen crowded with bustling traffic, was a
ghastly emptiness. Not even a tiny, wheeling speck betrayed the
presence of a bird. And below--the gas that was fatal to animal life
seemed to have stimulated vegetable growth--an illimitable sea of
green rolled untenanted to where the first ramparts of New York rose
against the sky. Roads, monorail lines, all the countless tracks of
civilization had disappeared beneath the green tide. Nature had taken
back its own.

Heartsick, he turned south, and followed the silver stream of the
Hudson. The river, lonely as the sky, seemed to drift oily and
sluggish down to plunge beneath the city at the lower end of the
Tappan Zee. Allan Dane came over New York, gazed down at the ruin of
its soaring towers, at the leaping arabesque of its street bridges. He
peered into vast rifts of tumbled, chaotic concrete and steel. Nothing
moved in all that spreading wonder that had housed twenty millions of
people.

Allan drifted lower, and saw that from what had been gardened
roof-parks, now a welter of strewn earth, the green things had spread
till they covered the heaped jetsam with a healing blanket of foliage.
Not all the city had been laid waste, however. Here and there, great
expanses of the cliff-like structures still stood, undamaged, and in
the midst of one of these areas he saw the high-piled edifice to which
he had been directed. Its roof was lush with vegetation but by
dextrous handling he set his helicopter down upon it.