the silence broken. A minute passed, two minutes, and
Hilary breathed a sigh of relief. The message had not gotten through.

Then it came--a tiny sparking, an intermittent hum. Hilary's heart
sank with hammering blows. He tried to read the signals, but they were
in code, or in the Mercutian tongue, which was just as bad. It was not
necessary, though. Headquarters _had_ heard; they _knew_.

Hilary did not waste an instant in vain regrets. Within an hour the
gorge would be a vicious trap; he must get his men out at once. What
then he did not know, nor bother. There was the more immediate
problem.

He went down the swinging ladder hand over hand, not pausing for the
rungs. Every instant was precious now. His hands scorched, but he did
not feel the pain.

His flying body collided thudding with a heavy bulk beneath. There was
a grunt, the rope jerked from his hands, and two bodies fell cursing,
entangled, to the ground. Luckily it was not far distant. He sprang
to his feet, found Grim heaving his bulk up more slowly.

"I was coming up after you," the giant growled. "You were gone too
long. That's the thanks I get."

Hilary had no time for idle talk.

"Attention, men," he snapped. "We leave at once. You have five minutes
to get your arms, ammunition clips and rations, light marching order."

Without a word they scattered alertly to their tasks. It was the
discipline of veterans.

"You didn't get the Mercutian?" Grim was troubled.

"I got him all right," answered his leader laconically, "but too late.
His message had gone through."

* * * * *

Five minutes later to the dot, the camp was lined up, accoutered
complete. They were silent, tense, but smartly erect. Hilary's flash
glowed over them in the dark. Then he nodded approvingly.

"Fine work, men. Up that ladder, one at a time," he said. "Each man
counts twenty slowly, one--two--three before he follows. Keep your
distance, and move fast."

The first man sprang to the ladder, went up swiftly. Twenty seconds
later, the next man's foot was on the bottom rung. Up and up they
went, one after the other, each man counting off and climbing. Hilary
watched them anxiously.

"Hope we make it," he muttered to Grim. "It'll take all of forty
minutes to evacuate, and the Mercutians may be on us by then."

It was almost forty minutes to the dot when Hilary's head emerged from
the cleft. He was the last man out. The men were lined up on a l