in
bright shivers. Formed from the predominant silicon of the planet, the
creatures were living glass!

For perhaps a quarter of an hour we were in the thick of them, hewing
until I thought my arms must fall, slashing and tearing at the ones that
had got underfoot and were clamping their tentacles around our legs.
Only for the space-suits, we should have, by this time, been overpowered
and torn into bits--and yet these garments could not be expected to hold
indefinitely.

* * * * *

But at last there was a breathing space. The crippled front ranks
dragged themselves away, and there was left around us a brief area of
sand, covered with coruscating splinters of glass. Garth got the breath
to say something or other encouraging. It was like old days at school.

Only this time the odds were all against us. We were still a good
hundred yards from the _Comet_, and in our path stood a solid wall of
the creatures. Even if we got free, they could outrace us to the goal.
And with our limited strength, we could not hope to kill them all. In a
minute or two, they would attack us again.

Somehow we must fight our way as long as we lasted. Perhaps they might
be frightened. We threw ourselves at the side next our goal. The line
gave perhaps a yard, then stiffened, and we found ourselves swallowed up
in a thick cloud of brown smoke.

Poison gas! It must be shot out of their bodies, at a cost so great that
it was kept as a last resort. Through the rolling vapor it was just
possible to see our opponents, but they made no forward move. They were
waiting for us to be overcome. Suppose their compound could eat through
even our helio-beryllium? But it did not. We were safe.

"Stand still, Garth," I whispered, counting on the radio to carry my
voice. "Let them think we're dead, and then give them a surprise."

"All right."

Long, long minutes.... If only they did not know that it was the
customary thing for a dead man to fall.... Slowly they began to move in.

Then Garth and I were upon them. They halted as if stupefied. We had
hacked our way half through their mass. The rest fled, and we began
running toward the _Comet_, praying that we might reach the ship before
they could get organized again. How we floundered through the sand in
wild and desperate haste.

* * * * *

Before we had covered half the distance, the pursuit began. There was no
attempt to drag us down d