Jeter broke the connection temporarily. Hadley could get him at any
moment. A buzzer would sound inside the almost noiseless cabin when
anyone wished to contact him over the radiophone.

Eyer was concentrating on the controls. The plane was climbing in great
sweeping spirals. Its speed was a hundred and fifty miles an hour. Their
air speed indicator was capable of registering eight hundred miles an
hour. They hoped to attain that speed and more, flying on an even keel
above ninety thousand feet.

Both Eyer and Jeter were perfect navigators. If, as they hoped, they
could reach ninety thousand or more, they could cross the whole United
States in four hours or less. They could quarter the country, winged
bloodhounds of space, seeking their quarry.

Jeter studied the sky above them through their special telescopes,
seeking some hint of the location of the point of departure of that
devastating column of light. He could think of no ray that would nullify
gravitation--yet that column of light had been the visual manifestation
that the thing had somehow been brought about.

If this were true, was the enemy vulnerable? Was his base of attack
capable of being destroyed or crippled if anything happened to the
column of light? There was no way of knowing--yet. A search of the sky
above Manhattan failed to disclose any visible substance from which the
light beam might emanate. That seemed to indicate some unbelievable
height. Yet, Kress must have reached that base. Else why had he been
destroyed and sent back to Jeter and Eyer as a challenge?

* * * * *

Jeter's mind went back to Kress. Frozen solid ... but that could have
been caused by his downward plunge through space. And what had happened
to Kress' plane? No word had been received concerning it up to the time
of the Jeter-Eyer departure. Had the "enemy" taken possession of it?

The whole thing seemed absurd. Nobody knew better than Jeter that he was
working literally and figuratively in the dark. He was doing little
better than guessing. He felt sure of but one thing, that the agency
which was wreaking the havoc was a human one, and he was perfectly
willing to match his wits and Eyer's against any human intelligence.

Jeter slipped into the cushioned seat beside Eyer.

The altimeter registered fifteen thousand feet. New York was just a blur
against the abysmal darkness under their careening wings.

"You've never ventured an opinion, T