substance that no ray, no electro-bullet can
penetrate. Every ship will be coated with it. And the Gorm here"--he
pointed to the oily lake--"will draw your proud cruisers down to
destruction, or thrust them far out into the uncharted spaces,
helpless, just as it pleases us. You wonder how it works? Look! Now it
attracts, and powerfully. But when I reverse the current passing
through it like this"--he leaned over and pulled a switch set in the
rock right by the edge--"it repels everything. We'll just stand off in
space and pick off your proud warships one by one, without a scratch
to ourselves. See?" He fairly hissed the last word.

Grant saw, and the cold sweat burst out on his forehead. His brain
raced desperately in a vain effort to find some way out, some method
of foiling this beast.

"You sure talk big, Miro," he said in bored fashion, feigning
indifference; "but it means nothing to me. The point is, what do you
intend doing with us?"

* * * * *

The Ganymedan's lips writhed. "Nothing at all to your pretty friend,"
he leered. "I have plans for her. But as for you--see these creatures
all about?"

"Well?"

"You are going to be one of them. They are passengers and crews who
had the misfortune to be alive when the captured ships were sprayed
with our gas. It does not kill. Oh, no! It just numbs their faculties,
paralyzes them. Then our surgeons get busy. They know how to remove
the memory and reasoning areas of the brain and leave just machines,
automata, to do our bidding. Clever, aren't they? When Earth is
captured, I intend subjecting all your damned breed to the operation.
They make very willing slaves, I've found. Two blasts on this toy"--he
raised the whistle to his lips--"and an Earth-Doora comes for you."

Nona sprang forward. "No, no, Miro. Please do not touch Mr. Pemberton.
I'll--I'll--"

"What will you?" The Ganymedan's pig-eyes devoured her.

"I'll--" Then, to Grant's eternal horror, she sank into Miro's arms.
The surprised look on Miro's face changed slowly to one of passion, as
he held her close to him with his great hairy arm.

"Nona!" Grant gasped and saw red. Heedless of the unwavering weapon at
his breast, he sprang. Miro snarled as he saw him coming. His finger
pressed down. But at that instant the Earth girl struck out with all
the power of her slender arm. It was not much of a blow, but it
managed to jar the weapon aside. The blue flame leaped hissing th