orrible, Jimmy!
Are they intending to conduct sapping operations against us like
engineers, or what?"

Dodd did not reply, and Tommy hardly expected any answer. As the two
men, now joined by Haidia, watched, they saw that the beetles were
actually digging themselves into the sand.

* * * * *

Within the space of an hour, by the time the first shafts of sunlight
began to stream into the room, there was to be seen only the massive,
rounded shells of the monsters as they squatted in the sand.

"Now you may fetch water," said Haidia, smiling at her lover. "No, you
do not need the shells," she added. "The beetles are finish. It is as
the wise men of my people told me."

Wondering, hesitating, Tommy and Dodd unlocked the front door. They
stood upon the threshold ready to bolt back again. But there was no
stirring among the beetle hosts.

Growing bolder, they advanced a few steps; then, shamed by Haidia's
courage, they followed her, still cautiously to the station.

Dodd shouted as he saw a water-tank, and a receptacle above it with a
water-cock. They let Haidia drink, then followed suit, and for a few
moments, as they appeased their thirst, the beetles were forgotten.

Then they turned back. There had been no movement in that line of shells
that glinted in the morning sunlight.

"Come, I shall show you," said Haidia confidently, advancing toward the
trench.

Dodd would have stopped her, but the girl moved forward quickly, eluded
him with a graceful, mirthful gesture, and stooped down over the trench.

She rose up, raising in her arms an empty beetle-shell!

Dodd, who had reached the trench before Tommy, turned round and yelled
to him excitedly. Tommy ran forward--and then he understood.

The shells were empty. The swarm, whose life cycle Bram had admitted he
did not understand, had just moulted!

It had moulted because the bodies, gorged with food, had grown too large
for the shells. In time, if left alone, the monsters would grow larger
shells, become invincible again. But just now they were defenseless as
new-born babes--and knew it.

Deep underneath the empty shells they had burrowed into the ground.
Everywhere at the bottom of the deep trenches were the naked, bestial
creatures, waving helpless tentacles and squirming over one another as
they strove to find shelter and security.

A sudden madness came over Tommy and Dodd. "Dynamite--there must be
dynamite!" Dodd shouted,