y taking them to Mercury?" I demanded.

"As nearly as I can make out, there is a race of men up there who are
subject to these beetles. This ship is radium propelled, and the men and
women are the slaves who work in the radium mines. Of course the workers
soon become sexless, but others are kept for breeding purposes to keep
the race alive. Through generations of in-breeding, the stock is about
played out and are getting too weak to be of much value.

"The Mercurians have been studying the whole universe to find a race
which will serve their purpose and they have chosen us to be the
victims. When their fleet gets here, they plan to capture thousands of
selected children and carry them to Mercury in order to infuse their
blood into the decadent race of slaves they have. Those who are not
suitable for breeding when they grow up will die as slaves in the radium
mines."

* * * * *

"Horrible!" I gasped. "Why are they taking children, Jim? Wouldn't
adults suit their purpose better?"

"They are afraid to take adults. On Mercury an earthman would have
muscles of unheard of power and adults would constantly strive to rise
against their masters. By getting children, they hope to raise them to
know nothing else than a life of slavery and get the advantage of their
strength without risk. It is a clever scheme."

"And are we to stand here and let them do it?"

"Not on your life, but we had better hold easy for a while. If I can get
a few minutes more with that brute I'll know enough about running this
ship that we can afford to do away with them. You have a pistol, haven't
you?"

"No."

"The devil! I thought you had. I have an automatic, but it only carries
eight shells. There are eleven of these insects and unless we can get
the jump on them, they'll do us. I saw what looks like a knife lying
near the instrument board; get over near it and get ready to grab it as
soon as you hear my pistol. These things are deaf and if I work it right
I may be able to do several of them in before they know what's
happening. When you attack, don't try to ram them in the back; their
backplates are an inch thick and will be proof against a knife thrust.
Aim at their eyes; if you can blind them, they'll be helpless. Do you
understand?"

"I'll do my best, Jim," I replied. "Since you have told me their plans I
am itching to get at them."

* * * * *

I edged over toward the kni