st."

Garin frowned at the map. He wasn't so sure about that explanation, but
Farson was paying the bills. The flyer shrugged away his uneasiness.
Much could be forgiven a man who allowed one to eat regularly again.

Four days later they set out. Helmly, one of the engineers, Rawlson, a
pilot, and Farson occupied the first plane. The other engineer and pilot
were in the second and Garin, with the extra supplies, was alone in the
third.

He was content to be alone as they took off across the blue-white waste.
His ship, because of its load, was loggy, so he did not attempt to
follow the other two into the higher lane. They were in communication by
radio and Garin, as he snapped on his earphones, remembered something
Farson had said that morning:

"The haze affects radio. On our trip near it the static was very bad.
Almost," with a laugh, "like speech in some foreign tongue."

As they roared over the ice Garin wondered if it might have been
speech--from, perhaps, a secret enemy expedition, such as the Kattack
one.

In his sealed cockpit he did not feel the bite of the frost and the ship
rode smoothly. With a little sigh of content he settled back against the
cushions, keeping to the course set by the planes ahead and above him.

Some five hours after they left the base, Garin caught sight of a dark
shadow far ahead. At the same time Farson's voice chattered in his
earphones.

"That's it. Set course straight ahead."

The shadow grew until it became a wall of purple-blue from earth to sky.
The first plane was quite close to it, diving down into the vapor.
Suddenly the ship rocked violently and swung earthward as if out of
control. Then it straightened and turned back. Garin could hear Farson
demanding to know what was the matter. But from the first plane there
was no reply.

As Farson's plane kept going Garin throttled down. The actions of the
first ship indicated trouble. What if that haze were a toxic gas?

"Close up, Featherstone!" barked Farson suddenly.

He obediently drew ahead until they flew wing to wing. The haze was just
before them and now Garin could see movement in it, oily, impenetrable
billows. The motors bit into it. There was clammy, foggy moisture on the
windows.

Abruptly Garin sensed that he was no longer alone. Somewhere in the
empty cabin behind him was another intelligence, a measuring power. He
fought furiously against it--against the very idea of it. But, after a
long, terrifying mom