oms above my head.

Mildred's confidence that the crabs would all gather at the ringing of
the gong had been mistaken. The two guards had been waiting at the
foot of the ladder, their flaming heat-rays ready for use.

As I dived back into the jungle, I heard two quick reports of the
rifle. I scrambled awkwardly to my feet, beneath the heavy pack. Ray
stood alert beside me, the smoking rifle in his hand. The giant crabs
had collapsed by the foot of the ladder, in grotesque and hideous
metal-bound heaps of red shell and twisted limb. Blood was oozing from
a ragged hole in the head of each.

"Glad they were here," Ray muttered. "I wanted to try the gun out on
'em. They're soft enough beneath the shell; the bullet tears 'em up
inside. Let's get a move on!"

He sprang past the revolting carcasses. I followed, holding my nose
against their nauseating, charnel-house odor. We scrambled up the
metal ladder.

As we climbed, I could hear the haunting melody of Mildred's wordless
song coming faint across the distance. Once I glanced back for a
moment, and glimpsed her tiny white figure above the black water, with
the thousands of green antennae rising in a luminous forest about her.

We reached the top of the cliff, where the opalescent river plunged
down in the flaming fall. Ray chose convenient boulders for shelter
and quickly we flung ourselves flat. Ray replaced the fired cartridges
in the rifle and leveled it across the rock before him. I unslung the
binoculars and focussed them.

"Watch 'em close," Ray muttered. "And tell me when to shoot."

* * * * *

The black lake lay below us, with the weird city of sapphire cylinders
on its floor. I got the glasses upon Mildred's white form. Soon she
dived from the turquoise pedestal, swam swiftly ashore and vanished in
the vivid fungous jungle. The wavering green antennae vanished below
the water; I watched the crabs swimming away. Some of them climbed out
of the water and lumbered off in various directions.

In fifteen minutes the slender white form of Mildred appeared at the
foot of the ladder. She sprang over the dead crabs and scrambled
nimbly up. Soon she was halfway up the face of the cliff, and there
had been no sign of discovery. My hopes ran high.

I was sweeping the whole plain with the binoculars, while Ray peered
through the telescopic sights of the rifle. Suddenly I saw a giant
crab pause as he lumbered along the edge of the black