es devised a plan.

These creatures did not eat. There was a tradition that at one time
they had had mouths, as I had, but that was not known. Their strength,
their vitality, came from the powerful mineral vapor which came forth
from the bowels of the earth. The ruling classes decided that if they
could control the supply of this vapor, they would have the whip hand,
and they set about realizing this condition.

* * * * *

It was quickly done. All the sources of supply, save one, were sealed.
This one source of supply was the cavern in which we stood. These were
members of the ruling class, and outside was the rabble, starved and
unhappy, living on the faint seepage of the vital fumes, without which
they became almost bodiless, and the helpless slaves of those within
the cavern.

These creatures, then, were boneless; as boneless as sponges, and,
like sponges, capable of absorbing huge quantities of a foreign
substance, which distended them and gave them weight. I could see,
now, why the rotund bodies sagged and flattened at the base, and why
six short, stubby legs were needed to support that body. There was
only tissue, unsupported by bone, to bear the weight!

This chief of the nine went on to show me how ruthlessly, how cruelly
those within the cavern ruled those without. The substance that fed
the flame had to be gathered and a great reservoir on the side of the
mountain kept filled. Great masses of dry, sweet grass, often changed,
must be harvested and brought to the entrance of the cavern, for
bedding. A score of other tasks kept the outsiders busy always--and
the driving force was that, did the slaves become disobedient, the
slight supply of mineral vapor available in the outside world would be
cut off utterly, and all outside would surely die, slowly and in
agony.

Those within the cavern were the rulers. They would always remain the
rulers, and those outside would remain the slaves to wait upon them.
And we--how strangely he pictured us, as he saw us!--were not to
return to our queer worlds, that we might bring many other ships like
the _Ertak_ back to interfere. No.

The pupils of his eyes contracted, and the leafy structure of his nose
fluttered as though with strong emotion.

No, we would not go back. He would give a signal to those of his
creatures who stood behind us--a sort of soldiery, I gathered--and our
heads, our legs, our arms, would be torn from our bodies. Th