lake. He rose
upright; his shining green antennae wavered. Then I saw him reaching
with a knobbed claw for a slender silver tube slung to his harness.

"Quick! The one by the lake! To the right of that canal!"

I pointed quickly. Ray swung his gun about, aimed. A broad red beam
flashed from the tube the thing carried, and fell upon the cliff. The
report of Ray's rifle rang thunderously in my ears. The red ray was
snapped off abruptly, and the giant crab rolled over into the black
water of the lake. Half a dozen of the huge crabs were in sight. They
all took alarm, probably having seen the flash of the red ray. They
raised grotesque heads, twisted stalked eyes and waved green antennae.
Some of them began to raise the metal tubes of the heat-ray.

"Let's get all there are in sight!" Ray muttered.

He began firing regularly, with deliberate precision. A few times he
had to take two shots, but ordinarily one was enough to bring down a
giant crab in a writhing red mass. Three times a red ray flashed out,
once at the girl clambering up the ladder, twice at our position above
the precipice. But the intense color of the ray announced its source,
and Ray stopped each before it could be focussed to do damage.

I looked over at Mildred and saw that she was still climbing bravely,
a little over a hundred feet below.

* * * * *

Then the great red crabs began to climb out of the water, heat-ray
tubes grasped in their claws. Ray fired as fast as he could load and
aim. Still he shot with deliberate care, and almost every shot was
effective.

Intense, ruby-red rays flashed up from the lake shore. Twice, one of
them beat scorchingly upon us for a moment. Once a rock beside us was
fused and cracked with the heat. But Ray fired rapidly, and the rays
winked out as fast as they were born.

He was powder-stained, black and grimy. The heat-ray had singed his
clothing. He was dripping perspiration. The gun was so hot that he
could hardly handle it. But still the angry bark of the rifle rang
out, almost with a deliberate rhythm. Ray was a fine shot in his youth
on his father's Arizona ranch, but his best shooting, I think, was
done from above that cascade of liquid fire, at the hordes of monster
scarlet crabs.

Mildred scrambled over the edge, unharmed. Her breast was heaving, but
her face was bright with joy.

"You are wonderful!" she gasped to Ray.

We seized the packs and beat a hurried retreat.